POLYPOSIS. DIVERTICULOSIS. UNSPECIFIC ULCEROUS COLITIS. CROHN’S DISEASE

POLYPOSIS. DIVERTICULOSIS. UNSPECIFIC ULCEROUS COLITIS. CROHN’S DISEASE.

 

POLYPOSIS

 

Polyps are non malignant tumors on legs that grow from mucosa.

 

Etiology and pathogenesis

 

Reasons of polyp’s appearance are disorders in embryonal development , inflammatory processes of mucosa and also viral infection.

 

Pathomorphology

 

Polypus of inflammatory origin differ from adenomatous ones by their incorrect form and size variety. They are soft, filled with blood, often with ulceration and hematomas. Such polypus usually combine with other signs of inflammation in intestine.

Adenomatous polypus are often part of syndromes. Thus, combination with non malignant tumors of bones, skin and soft tissues is characteric for Gardner’s syndrome, combination with focal melanosis of mucosa – for Peitz-Eggers’ syndrome, combination with brain tumors – for Turco’s syndrome.

 

Classification

 

By etiology:

· Innate (hereditary, family)

· Acquired (at inflammatory processes)

Separately they define also children (juvenile, innate and acquired).

By process’ spreading:

· Single

· Multiple

· Total (injury of all intestines).

By external appearance and microscopic structure:

· True (glandular, fleesy, from multi layer epithelium)

· False (hypertrophic at ulceric colitis, fibrose).

 

Symptoms and clinical course

 

Men get this disease in 2-3 times more than women. Single polypus of colon and rectum have usually latent course and are often revealed accidentally.

Multiple polypus may lead to diarrhea, bleeding, changes in morphological and biochemical blood composition. At this children do not devlop properly. At distal localization in some patients polypus prolapse and strangulate in anal ring causing pain. Low situated polypus irritate rectum and cause tenesmas, sometimes they cause prolapse of intestinal wall.

Among disease’s symptoms first palce belongs to disorders of defecation and blood in feces with further anemia, hypoproteinemia, decrease of workability. Fleesy polypus leads to disorders of water-salt and protein metabolism, because mucus’ excretion at defecation may achieve 1.5 liters,

At multiple polyposis they define triad of symptoms:

1.     Pigment spots (on the face, lips, mucosal membranes of cheeks, fingers, and other areas of covering epithelium).

2.     Polyposis of digestive tract.

3.     Hereditary character of disease.

Finger examination of rectum and observation with rectal mirror give a possibility to investigate its lower part. During this procedures you can reveal polypus of different size situated on jucosa of rectum and also polypus prolapsed with invaginate of sygmoid colon.

Irigography reveals single and multiple defects of filling, so called symptom of “shooted aim” that may be seen in different parts of colon. At presence of invaginate as complication of polypus there is charactering defect of filling.

With the help of rectoromanoscope you can examine rectum and sigmoid colon on average height 30 cm, and fibrocolonoscope is to examine all parts of colon. This investigation method gives a possibility to reveal exact place of polypus’ localization, its appearance including leg width, to provide excisional byopsia and also electrocoagulation.

 

Variants of clinical course and complications

 

Polypus of small size at the onset have latent course. With their growth during moving of feces may occur disorder of their completeness with further possible complications. More often is bleeding that in most cases occur defecation. Depending on the height of polypus’ localization in intestine blood may be dark red to bright red color. Blood loss may be from small, light to severe, with signs of small and incredible anemia.

In most patients polypus have a tendense to malignization. Provided biopsia in pre operation period with morphological investigation reveals malignant transformation of tissues and proves this diagnosis not in all cases. It depends on that in what part polypus becomes malignant. Final diagnosis may be put after the operation during histological investigation of all polypus.

Polypus of big size situated in rectum usually strangulate. During this strangulation takes place on the level of anal ring and is accompanied with severe pain. Not reducible polypus may necrotize.

Polypus are situated in caecum, colon and sigmoid colon. In the most motile areas they may lead to intestinal invagination. In this case there appear spastic pain, blood excretion with feces. During abdominal palpation they reveal painful infiltrate. Invagination may prolapse into rectal lumen.

 

Diagnostic program

 

1.     Anamnesis and physical data.

2.     Finger investigation of rectum.

3.     Investigation by rectal mirror.

4.     Rectoromanoscopy.

5.     Irigography.

6.     Fibrocolonoscopy.

7.     General analysis of blood and urine.

8.     Coagulogram

 

 

      

Polyps. Endoscopic view.

 

Differential diagnosis

 

Polypus of colon and rectum should be differentiated with malignant and non epithelial tumors, non specific ulcer colitis and rectal fissures.

Cancer of right part of colon ahs a course with incredible anemia (toxicoanemic form) due to absorption of tumor’s toxic products, their action on hemopoetic organs.

Cancer of left part of colon is usually accompanied with signs of obturative intestinal impassability. Additional examination (finger rectal examination, irigography, endoscopic methods) give a possibility to prove the diagnosis.

At chronic course of non specific ulcer colitis there is injured mucosa of intestine, and little islands of not injured mucosa between multiple big ulcers look like polypus, so called pseudopolyposis. Detailed anamnesis, specialities of clinical course of the disease, irigography and colonoscopy exclude presence of true polypus.

Not epithelial tumors (leyomyoma, lipoma) are situated under intestinal mucosa and at their small size do not cause any symptoms. With their growth mucosa is injured, there occurs bleeding with its signs. X-ray and endoscopic methods of investigation, and also histological investigation prove the final diagnosis.

Chronic fissure of rectum with not smooth edges and terminal tuberculum often simulates true polypus. Removal of this formation both with fissure and provided histological investigation help in proving of diagnosis.

 

Tactics and choice of treating method

 

Conservative method of treatment is rarely used. For this is used solution of green greater celandine for its introduction in enemas (3-4 grams of green mass for 1 kg of patient weight, on the average 50 g for adults). A celandine is ground down on a meat grinder, conduct in hot water in the ratio 1:10. A medical cycle includes 15–30 enemas. Per treatments course is conducted three cycles at intervals in one month. The low located polypuses from a stratified epithelium, pseudopolypuses and malignant polypuses are not treated by celandine.

Because of polypuses of small intestine and rectums are inclined to malignization, the basic method of its treatment is surgical .

Methods of operative treatment at polypus are divided into two groups:

1.                    Local operations (endoscopic electrocoagulation, polypus’s removal). Indication for electrocoaguclation is presence of single polypus oarrow leg, rarely – multiple polypus. Depending on the localization polypus on wide leg are removed through rectum of by laparotomy with further colotomy.

2.                    Radical operations as resection of separate segments of colon, right-side, left-side, subtotal colectomy or coleproctectomy are provided at multiple polypus. video   video2  video3

 

 

EMBRYOLOGY AND ANATOMY

Embryology

The embryonic gastrointestinal tract begins developing during the fourth week of gestation. The primitive gut is derived from the endoderm and divided into three segments: foregut, midgut, and hindgut. Both midgut and hindgut contribute to the colon, rectum, and anus.

The midgut develops into the small intestine, ascending colon, and proximal transverse colon, and receives blood supply from the superior mesenteric artery. During the sixth week of gestation, the midgut herniates out of the abdominal cavity, and then rotates 270 degrees counterclockwise around the superior mesenteric artery to return to its final position inside the abdominal cavity during the tenth week of gestation.

The hindgut develops into the distal transverse colon, descending colon, rectum, and proximal anus, all of which receive their blood supply from the inferior mesenteric artery. During the sixth week of gestation, the distal-most end of the hindgut, the cloaca, is divided by the urorectal septum into the urogenital sinus and the rectum.

The distal anal canal is derived from ectoderm and receives its blood supply from the internal pudendal artery. The dentate line divides the endodermal hindgut from the ectodermal distal anal canal.

Anatomy

The large intestine extends from the ileocecal valve to the anus. It is divided anatomically and functionally into the colon, rectum, and anal canal. The wall of the colon and rectum comprise five distinct layers: mucosa, submucosa, inner circular muscle, outer longitudinal muscle, and serosa. In the colon, the outer longitudinal muscle is separated into three teniae coli, which converge proximally at the appendix and distally at the rectum, where the outer longitudinal muscle layer is circumferential. In the distal rectum, the inner smooth-muscle layer coalesces to form the internal anal sphincter. The intraperitoneal colon and proximal one third of the rectum are covered by serosa; the mid and lower rectum lack serosa.

Colon Landmarks

The colon begins at the junction of the terminal ileum and cecum and extends 3 to 5 feet to the rectum. The rectosigmoid junction is found at approximately the level of the sacral promontory and is arbitrarily described as the point at which the three teniae coli coalesce to form the outer longitudinal smooth muscle layer of the rectum. The cecum is the widest diameter portion of the colon (normally 7.5 to 8.5 cm) and has the thinnest muscular wall. As a result, the cecum is most vulnerable to perforation and least vulnerable to obstruction. The ascending colon is usually fixed to the retroperitoneum. The hepatic flexure marks the transition to the transverse colon. The intraperitoneal transverse colon is relatively mobile, but is tethered by the gastrocolic ligament and colonic mesentery. The greater omentum is attached to the anterior/superior edge of the transverse colon. These attachments explain the characteristic triangular appearance of the transverse colon observed during colonoscopy. The splenic flexure marks the transition from the transverse colon to the descending colon. The attachments between the splenic flexure and the spleen (the lienocolic ligament) can be short and dense, making mobilization of this flexure during colectomy challenging. The descending colon is relatively fixed to the retroperitoneum. The sigmoid colon is the narrowest part of the large intestine and is extremely mobile. Although the sigmoid colon is usually located in the left lower quadrant, redundancy and mobility can result in a portion of the sigmoid colon residing in the right lower quadrant. This mobility explains why volvulus is most common in the sigmoid colon and why diseases affecting the sigmoid colon, such as diverticulitis, may occasionally present as right-sided abdominal pain. The narrow caliber of the sigmoid colon makes this segment of the large intestine the most vulnerable to obstruction.

Colon Vascular Supply

The arterial supply to the colon is highly variable (Fig. 28-1). In general, the superior mesenteric artery branches into the ileocolic artery (absent in up to 20% of people), which supplies blood flow to the terminal ileum and proximal ascending colon, the right colic artery, which supplies the ascending colon, and the middle colic artery, which supplies the transverse colon. The inferior mesenteric artery branches into the left colic artery, which supplies the descending colon, several sigmoidal branches, which supply the sigmoid colon, and the superior rectal artery, which supplies the proximal rectum. The terminal branches of each artery form anastomoses with the terminal branches of the adjacent artery and communicate via the marginal artery of Drummond. This arcade is complete in only 15 to 20% of people.

Colon Lymphatic Drainage

The lymphatic drainage of the colon originates in a network of lymphatics in the muscularis mucosa. Lymphatic vessels and lymph nodes follow the regional arteries. Lymph nodes are found on the bowel wall (epicolic), along the inner margin of the bowel adjacent to the arterial arcades (paracolic), around the named mesenteric vessels (intermediate), and at the origin of the superior and inferior mesenteric arteries (main). The sentinel lymph nodes are the first one to four lymph nodes to drain a specific segment of the colon, and are thought to be the first site of metastasis in colon cancer. The utility of sentinel lymph node dissection and analysis in colon cancer remains controversial.

Colon Nerve Supply

The colon is innervated by both sympathetic (inhibitory) and parasympathetic (stimulatory) nerves, which parallel the course of the arteries. Sympathetic nerves arise from T6-T12 and L1-L3. The parasympathetic innervation to the right and transverse colon is from the vagus nerve; the parasympathetic nerves to the left colon arise from sacral nerves S2-S4 to form the nervi erigentes.

Anorectal Landmarks

The rectum is approximately 12 to 15 cm in length. Three distinct submucosal folds, the valves of Houston, extend into the rectal lumen. Posteriorly, the presecral fascia separates the rectum from the presacral venous plexus and the pelvic nerves. At S4, the rectosacral fascia (Waldeyer’s fascia) extends forward and downward and attaches to the fascia propria at the anorectal junction. Anteriorly, Denonvilliers’ fascia separates the rectum from the prostate and seminal vesicles in men and from the vagina in women. The lateral ligaments support the lower rectum. The surgical anal canal measures 2 to 4 cm in length and is generally longer in men than in women. It begins at the anorectal junction and terminates at the anal verge. The dentate or pectinate line marks the transition point between columnar rectal mucosa and squamous anoderm. The 1 to 2 cm of mucosa just proximal to the dentate line shares histologic characteristics of columnar, cuboidal, and squamous epithelium and is referred to as the anal transition zone. The dentate line is surrounded by longitudinal mucosal folds, known as the columns of Morgagni, into which the anal crypts empty. These crypts are the source of cryptoglandular abscesses

In the distal rectum, the inner smooth muscle is thickened and comprises the internal anal sphincter that is surrounded by the subcutaneous, superficial, and deep external sphincter. The deep external anal sphincter is an extension of the puborectalis muscle. The puborectalis, iliococcygeus, and pubococcygeus muscles form the levator ani muscle of the pelvic floor.

Anorectal Vascular Supply

The superior rectal artery arises from the terminal branch of the inferior mesenteric artery and supplies the upper rectum. The middle rectal artery arises from the internal iliac; the presence and size of these arteries are highly variable. The inferior rectal artery arises from the internal pudendal artery, which is a branch of the internal iliac artery. A rich network of collaterals connects the terminal arterioles of each of these arteries, thus making the rectum relatively resistant to ischemia

The venous drainage of the rectum parallels the arterial supply. The superior rectal vein drains into the portal system via the inferior mesenteric vein. The middle rectal vein drains into the internal iliac vein. The inferior rectal vein drains into the internal pudendal vein, and subsequently into the internal iliac vein. A submucosal plexus deep to the columns of Morgagni forms the hemorrhoidal plexus and drains into all three veins.

Anorectal Lymphatic Drainage

Lymphatic drainage of the rectum parallels the vascular supply. Lymphatic channels in the upper and middle rectum drain superiorly into the inferior mesenteric lymph nodes. Lymphatic channels in the lower rectum drain both superiorly into the inferior mesenteric lymph nodes and laterally into the internal iliac lymph nodes. The anal canal has a more complex pattern of lymphatic drainage. Proximal to the dentate line, lymph drains into both the inferior mesenteric lymph nodes and the internal iliac lymph nodes. Distal to the dentate line, lymph primarily drains into the inguinal lymph nodes, but can also drain into the inferior mesenteric lymph nodes and internal iliac lymph nodes.

Anorectal Nerve Supply

Both sympathetic and parasympathetic nerves innervate the anorectum. Sympathetic nerve fibers are derived from L1-L3 and join the preaortic plexus. The preaortic nerve fibers then extend below the aorta to form the hypogastric plexus, which subsequently joins the parasympathetic fibers to form the pelvic plexus. Parasympathetic nerve fibers are known as the nervi erigentes and originate from S2-S4. These fibers join the sympathetic fibers to form the pelvic plexus. Sympathetic and parasympathetic fibers then supply the anorectum and adjacent urogenital organs.

The internal anal sphincter is innervated by sympathetic and parasympathetic nerve fibers; both types of fibers inhibit sphincter contraction. The external anal sphincter and puborectalis muscles are innervated by the inferior rectal branch of the internal pudendal nerve. The levator ani receives innervation from both the internal pudendal nerve and direct branches of S3 to S5. Sensory innervation to the anal canal is provided by the inferior rectal branch of the pudendal nerve. While the rectum is relatively insensate, the anal canal below the dentate line is sensate.

Congenital Anomalies

Perturbation of the embryologic development of the midgut and hindgut may result in anatomic abnormalities of the colon, rectum, and anus. Failure of the midgut to rotate and return to the abdominal cavity during the tenth week of gestation results in varying degrees of intestinal malrotation and colonic nonfixation. Failure of canalization of the primitive gut can result in colonic duplication. Incomplete descent of the urogenital septum may result in imperforate anus and associated fistulas to the genitourinary tract. Many infants with congenital anomalies of the hindgut have associated abnormalities in the genitourinary tract.

 

Normal Physiology

Fluid and Electrolyte Exchanges

Water, Sodium, Potassium, Chloride, Bicarbonate, and Ammonia

The colon is a major site for water absorption and electrolyte exchange. Approximately 90% of the water contained in ileal fluid is absorbed in the colon (1000 to 2000 mL/d), and up to 5000 mL of fluid can be absorbed daily. Sodium is absorbed actively via a Na-K ATPase. The colon can absorb up to 400 mEq of sodium per day. Water accompanies the transported sodium and is absorbed passively along an osmotic gradient. Potassium is actively secreted into the colonic lumen and absorbed by passive diffusion. Chloride is absorbed actively via a chloride–bicarbonate exchange.

Bacterial degradation of protein and urea produces ammonia. Ammonia is subsequently absorbed and transported to the liver. Absorption of ammonia depends in part upon intraluminal pH. A decrease in colonic bacteria (e.g., broad spectrum antibiotic usage) and/or a decrease in intraluminal pH (e.g., lactulose administration) will decrease ammonia absorption.

Short-Chain Fatty Acids

Short-chain fatty acids (acetate, butyrate, and propionate) are produced by bacterial fermentation of dietary carbohydrates. Short-chain fatty acids are an important source of energy for the colonic mucosa, and metabolism by colonocytes provides energy for processes such as active transport of sodium. Lack of a dietary source for production of short-chain fatty acids, or diversion of the fecal stream by an ileostomy or colostomy, may result in mucosal atrophy and “diversion colitis.”

Colonic Microflora and Intestinal Gas

Approximately 30% of fecal dry weight is composed of bacteria (10¹¹ to 10¹² bacteria/g of feces). Anaerobes are the predominant class of microorganism, and Bacteroides species are the most common (10¹¹ to 10¹² organisms/mL). Escherichia coli are the most numerous aerobes (10⁸ to 10¹⁰ organisms/mL). Endogenous microflora are crucial for the breakdown of carbohydrates and proteins in the colon and participate in the metabolism of bilirubin, bile acids, estrogen, and cholesterol. Colonic bacteria also are necessary for production of vitamin K. Endogenous bacteria also are thought to suppress the emergence of pathogenic microorganisms, such as Clostridium difficile. However, the high bacterial load of the large intestine may contribute to sepsis in critically ill patients and may contribute to intra-abdominal sepsis, abscess, and wound infection following colectomy.

Intestinal gas arises from swallowed air, diffusion from the blood, and intraluminal production. Nitrogen, oxygen, carbon dioxide, hydrogen, and methane are the major components of intestinal gas. Nitrogen and oxygen are largely derived from swallowed air. Carbon dioxide is produced by the reaction of bicarbonate and hydrogen ions, and by the digestion of triglycerides to fatty acids. Hydrogen and methane are produced by colonic bacteria. The production of methane is highly variable. The gastrointestinal tract usually contains between 100 and 200 mL of gas and 400 to 1200 mL per day are released as flatus, depending upon the type of food ingested.

Motility, Defecation, and Continence

Motility

Unlike the small intestine, the large intestine does not demonstrate cyclic motor activity characteristic of the migratory motor complex. Instead, the colon displays intermittent contractions of either low or high amplitude. Low-amplitude, short-duration contractions occur in bursts and appear to move the colonic contents both antegrade and retrograde. It is thought that these bursts of motor activity delay colonic transit and thus increase the time available for absorption of water and exchange of electrolytes. High-amplitude contractions occur in a more coordinated fashion and create “mass movements.” Bursts of “rectal motor complexes” also have been described. In general, cholinergic activation increases colonic motility.

Defecation

Defecation is a complex, coordinated mechanism involving colonic mass movement, increased intra-abdominal and rectal pressure, and relaxation of the pelvic floor. Distention of the rectum causes a reflex relaxation of the internal anal sphincter (the rectoanal inhibitory reflex) that allows the contents to make contact with the anal canal. This “sampling reflex” allows the sensory epithelium to distinguish solid stool from liquid stool and gas. If defecation does not occur, the rectum relaxes and the urge to defecate passes (the accommodation response). Defecation proceeds by coordination of increasing intra-abdominal pressure via the Valsalva maneuver, increased rectal contraction, relaxation of the puborectalis muscle, and opening of the anal canal.

Continence

The maintenance of fecal continence is at least as complex as the mechanism of defecation. Continence requires adequate rectal wall compliance to accommodate the fecal bolus, appropriate neurogenic control of the pelvic floor and sphincter mechanism, and functional internal and external sphincter muscles. At rest, the puborectalis muscle creates a “sling” around the distal rectum, forming a relatively acute angle that distributes intraabdominal forces onto the pelvic floor. With defecation, this angle straightens, allowing downward force to be applied along the axis of the rectum and anal canal. The internal and external sphincters are tonically active at rest. The internal sphincter is responsible for most of the resting, involuntary sphincter tone (resting pressure). The external sphincter is responsible for most of the voluntary sphincter tone (squeeze pressure). Branches of the pudendal nerve innervate both the internal and external sphincter. Finally, the hemorrhoidal cushions may contribute to continence by mechanically blocking the anal canal. Thus, impaired continence may result from poor rectal compliance, injury to the internal and/or external sphincter or puborectalis, or nerve damage or neuropathy.

 

Clinical Evaluation

Clinical Assessment

A complete history and physical examination is the starting point for evaluating any patient with suspected disease of the colon and rectum. Special attention should be paid to the patient’s past medical and surgical history to detect underlying conditions that might contribute to a gastrointestinal problem. If patients have had prior intestinal surgery, it is essential that one understand the resultant gastrointestinal anatomy. In addition, family history of colorectal disease, especially inflammatory bowel disease, polyps, and colorectal cancer, is crucial. Medication use must be detailed as many drugs cause gastrointestinal symptoms. Before recommending operative intervention, the adequacy of medical treatment must be ascertained. In addition to examining the abdomen, visual inspection of the anus and perineum and careful digital rectal exam are essential.

Endoscopy

Anoscopy

The anoscope is a useful instrument for examination of the anal canal. Anoscopes are made in a variety of sizes and measure approximately 8 cm in length. A larger anoscope provides better exposure for anal procedures such as rubber band ligation or sclerotherapy of hemorrhoids. The anoscope, with obturator in place, should be adequately lubricated and gently inserted into the anal canal. The obturator is withdrawn, inspection of the visualized anal canal is done, and the anoscope should then be withdrawn. It is rotated 90 degrees and reinserted to allow visualization of all four quadrants of the canal. If the patient complains of severe perianal pain and cannot tolerate a digital rectal examination, anoscopy should not be attempted without anesthesia.

Proctoscopy

The rigid proctoscope is useful for examination of the rectum and distal sigmoid colon and is occasionally used therapeutically. The standard proctoscope is 25 cm in length and available in various diameters. Most often, a 15- or 19-mm diameter proctoscope is used for diagnostic examinations. The large (25-mm diameter) proctoscope is useful for procedures such as polypectomy, electrocoagulation, or detorsion of a sigmoid volvulus. A smaller “pediatric” proctoscope (11-mm diameter) is better tolerated by patients with anal stricture. Suction is necessary for an adequate proctoscopic examination.

Flexible Sigmoidoscopy and Colonoscopy

Video or fiberoptic flexible sigmoidoscopy and colonoscopy provide excellent visualization of the colon and rectum. Sigmoidoscopes measure 60 cm in length. Full depth of insertion may allow visualization as high as the splenic flexure, although the mobility and redundancy of the sigmoid colon often limit the extent of the examination. Partial preparation with enemas is usually adequate for sigmoidoscopy and most patients can tolerate this procedure without sedation. Colonoscopes measure 100 to 160 cm in length and are capable of examining the entire colon and terminal ileum. A complete oral bowel preparation is usually necessary for colonoscopy and the duration and discomfort of the procedure usually require conscious sedation. Both sigmoidoscopy and colonoscopy can be used diagnostically and therapeutically. Electrocautery should generally not be used in the absence of a complete bowel preparation because of the risk of explosion of intestinal methane or hydrogen gases. Diagnostic colonoscopes possess a single channel through which instruments such as snares, biopsy forceps, or electrocautery can be passed; this channel also provides suction and irrigation capability. Therapeutic colonoscopes possess two channels to allow simultaneous suction/irrigation and the use of snares, biopsy forceps, or electrocautery.

Imaging

Plain X-Rays and Contrast Studies

Despite advanced radiologic techniques, plain x-rays and contrast studies continue to play an important role in the evaluation of patients with suspected colon and rectal diseases. Plain x-rays of the abdomen (supine, upright, and diaphragmatic views) are useful for detecting free intra-abdominal air, bowel gas patterns suggestive of small or large bowel obstruction, and volvulus. Contrast studies are useful for evaluating obstructive symptoms, delineating fistulous tracts, and diagnosing small perforations or anastomotic leaks. While Gastrografin cannot provide the mucosal detail provided by barium, this water-soluble contrast agent is recommended if perforation or leak is suspected. Double-contrast barium enema has been reported to be 70 to 90% sensitive for the detection of mass lesions greater than 1 cm in diameter. 1 Detection of small lesions can be extremely difficult, especially in a patient with extensive diverticulosis. For this reason, a colonoscopy is preferred for evaluating nonobstructing mass lesions in the colon. Double-contrast barium enema has been used as a back-up examination if colonoscopy is incomplete.

Computed Tomography

Computed tomography (CT) is commonly employed in the evaluation of patients with abdominal complaints. Its utility is primarily in the detection of extraluminal disease, such as intra-abdominal abscesses and pericolic inflammation, and in staging colorectal carcinoma, because of its sensitivity in detection of hepatic metastases. 2 Extravasation of oral or rectal contrast may also confirm the diagnosis of perforation or anastomotic leak. Nonspecific findings such as bowel wall thickening or mesenteric stranding may suggest inflammatory bowel disease, enteritis/colitis, or ischemia. A standard CT scan is relatively insensitive for the detection of intraluminal lesions.

Virtual Colonoscopy

Virtual colonoscopy is a new radiologic technique that is designed to overcome some of the limitations of traditional CT scanning. This technology uses helical CT and three-dimensional reconstruction to detect intraluminal colonic lesions. Oral bowel preparation, oral and rectal contrast, and colon insufflation are used to maximize sensitivity. Early evaluation of virtual colonoscopy suggests that accuracy may approach that of colonoscopy for detection of lesions 1 cm in diameter or greater.

Magnetic Resonance Imaging

The main use of magnetic resonance imaging (MRI) in colorectal disorders is in evaluation of pelvic lesions. MRI is more sensitive than CT for detecting bony involvement or pelvic sidewall extension of rectal tumors. MRI also can be helpful in the detection and delineation of complex fistulas in ano. The use of an endorectal coil may increase sensitivity.

Positron Emission Tomography

Positron emission tomography (PET) is used for imaging tissues with high levels of anaerobic glycolysis, such as malignant tumors. 18 F-fluorodeoxyglucose (FDG) is injected as a tracer; metabolism of this molecule then results in positron emission. PET has been used as an adjunct to CT in the staging of colorectal cancer and may prove useful in discriminating recurrent cancer from fibrosis. At present, the efficacy and utility of PET in the detection of recurrent and/or metastatic colorectal cancer remains unproven.

Angiography

Angiography is occasionally used for the detection of bleeding within the colon or small bowel. To visualize hemorrhage angiographically, bleeding must be relatively brisk (approximately 0.5 to 1.0 mL per minute). If extravasation of contrast is identified, infusion of vasopressin or angiographic embolization can be therapeutic.

Endorectal and Endoanal Ultrasound

Endorectal ultrasound is primarily used to evaluate the depth of invasion of neoplastic lesions in the rectum. The normal rectal wall appears as a five-layer structure (Fig. 28-6). Ultrasound can reliably differentiate most benign polyps from invasive tumors based upon the integrity of the submucosal layer. Ultrasound can also differentiate superficial T1-T2 from deeper T3-T4 tumors. Overall, the accuracy of ultrasound in detecting depth of mural invasion ranges between 81 and 94%. 3 This modality also can detect enlarged perirectal lymph nodes, which may suggest nodal metastases; accuracy of detection of pathologically positive lymph nodes is 58 to 83%. Ultrasound may also prove useful for early detection of local recurrence after surgery.

Endoanal ultrasound is used to evaluate the layers of the anal canal. Internal anal sphincter, external anal sphincter, and puborectalis muscle can be differentiated. Endoanal ultrasound is particularly useful for detecting sphincter defects and for outlining complex anal fistulas.

Physiologic and Pelvic Floor Investigations

Anorectal physiologic testing uses a variety of techniques to investigate the function of the pelvic floor. These techniques are useful in the evaluation of patients with incontinence, constipation, rectal prolapse, obstructed defecation, and other disorders of the pelvic floor.

Manometry

Anorectal manometry is performed by placing a pressure-sensitive catheter in the lower rectum. The catheter is then withdrawn through the anal canal and pressures recorded. A balloon attached to the tip of the catheter also can be used to test anorectal sensation. The resting pressure in the anal canal reflects the function of the internal anal sphincter (normal: 40 to 80 mm Hg), while the squeeze pressure, defined as the maximum voluntary contraction pressure minus the resting pressure, reflects function of the external anal sphincter (normal: 40 to 80 mm Hg above resting pressure). The high-pressurezone estimates the length of the anal canal (normal: 2.0 to 4.0 cm). The rectoanal inhibitory reflex can be detected by inflating a balloon in the distal rectum; absence of this reflex is characteristic of Hirschsprung’s disease.

Neurophysiology

Neurophysiologic testing assesses function of the pudendal nerves and recruitment of puborectalis muscle fibers. Pudendal nerve terminal motor latency measures the speed of transmission of a nerve impulse through the distal pudendal nerve fibers (normal: 1.8 to 2.2 msec); prolonged latency suggests the presence of neuropathy. EMG recruitment assesses the contraction and relaxation of the puborectalis muscle during attempted defecation. Normally, recruitment increases when a patient is instructed to “squeeze,” and decreases when a patient is instructed to “push.” Inappropriate recruitment is an indication of paradoxical contraction (nonrelaxation of the puborectalis). Needle EMG has been used to map both the pudendal nerves and the anatomy of the internal and external sphincters. However, this examination is painful and poorly tolerated by most patients. Needle EMG has largely been replaced by pudendal nerve motor-latency testing to assess pudendal nerve function and endoanal ultrasound to map the sphincters.

Rectal Evacuation Studies

Rectal evacuation studies include the balloon expulsion test and video defecography. Balloon expulsion assesses a patient’s ability to expel an intrarectal balloon. Video defecography provides a more detailed assessment of defecation. In this test, barium paste is placed in the rectum and defecation is then recorded fluoroscopically. Defecography is used to differentiate nonrelaxation of the puborectalis, obstructed defecation, increased perineal descent, rectal prolapse and intussusception, rectocele, and enterocele. The addition of vaginal contrast and intraperitoneal contrast is useful in delineating complex disorders of the pelvic floor.

Laboratory Studies

Fecal Occult Blood Testing

Fecal occult blood testing (FOBT) is used as a screening test for colonic neoplasms in asymptomatic, average-risk individuals. The efficacy of this test is based upon serial testing because the majority of colorectal malignancies will bleed intermittently. FOBT has been a nonspecific test for peroxidase contained in hemoglobin; consequently, occult bleeding from any gastrointestinal source will produce a positive result. Similarly, many foods (red meat, some fruits and vegetables, and vitamin C) will produce a false-positive result. Patients were counseled to eat a restricted diet for 2 to 3 days prior to the test. Increased specificity is now possible by using immunochemical FOBT. These tests rely on monoclonal or polyclonal antibodies to react with the intact globin portion of human hemoglobin. Because globin does not survive in the upper gastrointestinal tract, the immunochemical tests are more specific for identifying occult bleeding from the colon or rectum. Dietary restrictions are not necessary. Any positive FOBT mandates further investigation, usually by colonoscopy.

Stool Studies

Stool studies are often helpful in evaluating the etiology of diarrhea. Wet-mount examination reveals the presence of fecal leukocytes, which may suggest colonic inflammation or the presence of an invasive organism such as invasive E. coli or Shigella. Stool cultures can detect pathogenic bacteria, ova, and parasites. C. difficile colitis is diagnosed by detecting bacterial toxin in the stool. 4 Steatorrhea may be diagnosed by adding Sudan red stain to a stool sample.

Serum Tests

Specific laboratory tests that should be performed will be dictated by the clinical scenario. Preoperative studies generally include a complete blood count and electrolyte panel. The addition of coagulation studies, liver function tests, and blood typing/cross-matching depends upon the patient’s medical condition and the proposed surgical procedure.

Tumor Markers

Carcinoembryonic antigen (CEA) may be elevated in 60 to 90% of patients with colorectal cancer. Despite this, CEA is not an effective screening tool for this malignancy. Many practitioners follow serial CEA levels after curative-intent surgery in order to detect early recurrence of colorectal cancer. However, this tumor marker is nonspecific, and no survival benefit has yet been proven. Other biochemical markers (ornithine decarboxylase, urokinase) have been proposed, but none has yet proven sensitive or specific for detection, staging, or predicting prognosis of colorectal carcinoma. 5

Genetic Testing

Although familial colorectal cancer syndromes, such as familial adenomatous polyposis (FAP) and hereditary nonpolyposis colon cancer (HNPCC) are rare, information about the specific genetic abnormalities underlying these disorders has led to significant interest in the role of genetic testing for colorectal cancer. 6 Tests for mutations in the adenomatous polyposis coli (APC) gene responsible for FAP, and in mismatch repair genes responsible for HNPCC, are commercially available and extremely accurate in families with known mutations. Although many of these mutations are also present in sporadic colorectal cancer, the accuracy of genetic testing in average-risk individuals is considerably lower and these tests are not recommended for screening. Because of the potential psychosocial implications of genetic testing, it is strongly recommended that professional genetic counselors be involved in the care of any patient considering these tests.

Evaluation of Common Symptoms

Pain

Abdominal Pain

Abdominal pain is a nonspecific symptom with a myriad of causes. Abdominal pain related to the colon and rectum can result from obstruction (either inflammatory or neoplastic), inflammation, perforation, or ischemia. Plain x-rays and judicious use of contrast studies and/or a CT scan can often confirm the diagnosis. Gentle retrograde contrast studies (barium or Gastrografin enema) may be useful in delineating the degree of colonic obstruction. Sigmoidoscopy and/or colonoscopy performed by an experienced endoscopist can assist in the diagnosis of ischemic colitis, infectious colitis, and inflammatory bowel disease. However, if perforation is suspected, colonoscopy and/or sigmoidoscopy are generally contraindicated. Evaluation and treatment of abdominal pain from a colorectal source should follow the usual surgical principles of a thorough history and physical examination, appropriate diagnostic tests, resuscitation, and appropriately timed surgical intervention.

Pelvic Pain

Pelvic pain can originate from the distal colon and rectum or from adjacent urogenital structures. Tenesmus may result from proctitis or from a rectal or retrorectal mass. Cyclical pain associated with menses, especially when accompanied by rectal bleeding, suggests a diagnosis of endometriosis. Pelvic inflammatory disease also can produce significant abdominal and pelvic pain. The extension of a peridiverticular abscess or periappendiceal abscess into the pelvis may also cause pain. CT scan and/or MRI may be useful in differentiating these diseases. Proctoscopy (if tolerated) also can be helpful. Occasionally, laparoscopy will yield a diagnosis.

Anorectal Pain

Anorectal pain is most often secondary to an anal fissure or perirectal abscess and/or fistula. Physical examination can usually differentiate these conditions. Other, less common causes of anorectal pain include anal canal neoplasms, perianal skin infection, and dermatologic conditions. Proctalgia fugax results from levator spasm and may present without any other anorectal findings. Physical exam is critical in evaluating patients with anorectal pain. If a patient is too tender to examine in the office, an examination under anesthesia is necessary. MRI may be helpful in select cases where the etiology of pain is elusive.

Lower Gastrointestinal Bleeding

The first goal in evaluating and treating a patient with gastrointestinal hemorrhage is adequate resuscitation. The principles of ensuring a patent airway, supporting ventilation, and optimizing hemodynamic parameters apply and coagulopathy and/or thrombocytopenia should be corrected. The second goal is to identify the source of hemorrhage. Because the most common source of gastrointestinal hemorrhage is esophageal, gastric, or duodenal, nasogastric aspiration should always be performed; return of bile suggests that the source of bleeding is distal to the ligament of Treitz. If aspiration reveals blood or nonbile secretions, or if symptoms suggest an upper intestinal source, esophagogastroduodenoscopy is performed. Anoscopy and/or limited proctoscopy can identify hemorrhoidal bleeding. A technetium-99 (^99mTc)-tagged red blood cell (RBC) scan is extremely sensitive and is able to detect as little as 0.1 mL/h of bleeding; however, localization is imprecise. If the ^99mTc-tagged RBC scan is positive, angiography can then be employed to localize bleeding. Infusion of vasopressin or angioembolization may be therapeutic. Alternatively, a catheter can be left in the bleeding vessel to allow localization at the time of laparotomy. If the patient is hemodynamically stable, a rapid bowel preparation (over 4 to 6 hours) can be performed to allow colonoscopy. Colonoscopy may identify the cause of the bleeding, and cautery or injection of epinephrine into the bleeding site may be used to control hemorrhage. Colectomy may be required if bleeding persists despite these interventions. Intraoperative colonoscopy and/or enteroscopy may assist in localizing bleeding. If colectomy is required, a segmental resection is preferred if the bleeding source can be localized. “Blind” subtotal colectomy may very rarely be required in a patient who is hemodynamically unstable with ongoing colonic hemorrhage of an unknown source. In this setting, it is crucial to irrigate the rectum and examine the mucosa by proctoscopy to ensure that the source of bleeding is not distal to the resection margin

Occult blood loss from the gastrointestinal tract may manifest as iron-deficiency anemia or may be detected with fecal occult blood testing. Because coloeoplasms bleed intermittently and rarely present with rapid hemorrhage, the presence of occult fecal blood should always prompt a colonoscopy. Unexplained iron-deficiency anemia is also an indication for colonoscopy.

Hematochezia is commonly caused by hemorrhoids or fissure. Sharp, knife-like pain and bright-red rectal bleeding with bowel movements suggest the diagnosis of fissure. Painless, bright-red rectal bleeding with bowel movements is often secondary to a friable internal hemorrhoid that is easily detected by anoscopy. In the absence of a painful, obvious fissure, any patient with rectal bleeding should undergo a careful digital rectal examination, anoscopy, and proctosigmoidoscopy. Failure to diagnose a source in the distal anorectum should prompt colonoscopy.

Constipation and Obstructed Defecation

Constipation is an extremely common complaint, affecting more than 4 million people in the United States. Despite the prevalence of this problem, there is lack of agreement about an appropriate definition of constipation. Patients may describe infrequent bowel movements, hard stools, or excessive straining. A careful history of these symptoms often clarifies the nature of the problem.

Constipation has a myriad of causes. Underlying metabolic, pharmacologic, endocrine, psychologic, and neurologic causes often contribute to the problem. A stricture or mass lesion should be excluded by colonoscopy or barium enema. After these causes have been excluded, evaluation focuses upon differentiating slow-transit constipation from outlet obstruction. Transit studies, in which radiopaque markers are swallowed and then followed radiographically, are useful for diagnosing slow-transit constipation. Anorectal manometry and electromyography can detect nonrelaxation of the puborectalis, which contributes to outlet obstruction. The absence of an anorectal inhibitory reflex suggests Hirschsprung’s disease and may prompt a rectal mucosal biopsy. Defecography can identify rectal prolapse, intussusception, rectocele, or enterocele.

Medical management is the mainstay of therapy for constipation and includes fiber, increased fluid intake, and laxatives. Outlet obstruction from nonrelaxation of the puborectalis often responds to biofeedback. 7 Surgery to correct rectocele and rectal prolapse has a variable effect on symptoms of constipation, but can be successful in selected patients. Subtotal colectomy is considered only for patients with severe slow-transit constipation (colonic inertia) refractory to maximal medical interventions. While this operation almost always increases bowel movement frequency, complaints of diarrhea, incontinence, and abdominal pain are not infrequent, and patients should be carefully selected. 8

Diarrhea and Irritable Bowel Syndrome

Diarrhea is also a common complaint and is usually a self-limited symptom of infectious gastroenteritis. If diarrhea is chronic or is accompanied by bleeding or abdominal pain, further investigation is warranted. Bloody diarrhea and pain are characteristic of colitis; etiology can be an infection (invasive E. coli, Shigella, Salmonella, Campylobacter, Entamoeba histolytica, or C. difficile), inflammatory bowel disease (ulcerative colitis or Crohn’s colitis), or ischemia. Stool wet-mount and culture can often diagnose infection. Sigmoidoscopy or colonoscopy can be helpful in diagnosing inflammatory bowel disease or ischemia. However, if the patient has abdominal tenderness, particularly with peritoneal signs, or any other evidence of perforation, endoscopy is contraindicated.

Chronic diarrhea may present a more difficult diagnostic dilemma. Chronic ulcerative colitis, Crohn’s colitis, infection, malabsorption, and short gut syndrome can cause chronic diarrhea. Rarely, carcinoid syndrome and islet cell tumors (vasoactive intestinal peptide-secreting tumor [VIPoma], somatostatinoma, gastrinoma) present with this symptom. Large villous lesions may cause secretory diarrhea. Collagenous colitis can cause diarrhea without any obvious mucosal abnormality. Along with stool cultures, tests for malabsorption, and metabolic investigations, colonoscopy can be invaluable in differentiating these causes. Biopsies should be taken even if the colonic mucosa appears grossly normal.

Irritable bowel syndrome is a particularly troubling constellation of symptoms consisting of crampy abdominal pain, bloating, constipation, and urgent diarrhea. Work-up reveals no underlying anatomic or physiologic abnormality. Once other disorders have been excluded, dietary restrictions and avoidance of caffeine, alcohol, and tobacco may help to alleviate symptoms. Antispasmodics and bulking agents may be helpful.

Incontinence

The incidence of fecal incontinence has been estimated to occur in 10 to 13 individuals per 1000 people older than age 65 years. Incontinence ranges in severity from occasional leakage of gas and liquid stool to daily loss of solid stool. The underlying cause of incontinence is often multifactorial and diarrhea is often contributory. In general, causes of incontinence can be classified as neurogenic or anatomic. Neurogenic causes include diseases of the central nervous system and spinal cord along with pudendal nerve injury. Anatomic causes include congenital abnormalities, procidentia, overflow incontinence secondary to impaction or neoplasm, and trauma. The most common traumatic cause of incontinence is injury to the anal sphincter during vaginal delivery. Other causes include anorectal surgery, impalement, and pelvic fracture.

After a thorough medical evaluation to detect underlying conditions that might contribute to incontinence, evaluation focuses on assessment of the anal sphincter and pudendal nerves. Pudendal nerve terminal motor latency testing may detect neuropathy. Anal manometry can detect low resting and squeeze pressures. Defecography can detect rectal prolapse. Endoanal ultrasound is invaluable in diagnosing sphincter defects.

 

DIVERTICULAR DISEASE OF THE COLON

Diverticula are saclike protrusions of the colonic wall, varying in size from a few millimeters to several centimeters. True diverticula contain all layers of the colon wall and are believed to be congenital. They are very uncommon in the colon. False or pseudodiverticula represent herniations of the mucosa and submucosa through the circular muscle of the bowel wall. Unless otherwise stated in the text, the term diverticula refers to the predominant lesion, namely, colonic pseudodiverticula. The term diverticulosis simply indicates the presence of multiple diverticula of the colon.

PREVALENCE, PATHOGENESIS, AND PATHOLOGIC ANATOMY

The prevalence of diverticular disease in the general population ranges between 35% and 50%, as estimated by several large autopsy and radiographic series. 13 Prevalence directly correlates with age, estimated to be less than 5% at age 40, increasing to 30% by age 60, and as high as 65% by age 85. 25 Males and females appear to be affected equally. Geographically, diverticular disease is much more common in the United States and Western Europe than in other less industrialized regions such as Africa, South America, and Asia. Although diet is thought by many to contribute significantly to the development of diverticular disease, the complete etiology is likely to involve other, as yet unrecognized, factors. For example, diverticular disease in Asian populations is localized predominantly to the right colon, in distinct contrast to the left-sided predilection observed in Western civilizations. Such variations in the anatomic distribution of diverticula among civilizations might suggest that factors other than diet alone exert a substantial influence on the character of this disease worldwide.

Mechanical Factors. Clinical studies within the past 30 years have implicated low fiber diets as a prominent etiologic factor in the development of diverticular disease. 24^,  25 Diets lacking vegetable fiber are presumed to predispose to the development of diverticula by altering colonic motility. Colonic motility is a complex process serving to transport feces distally while also permitting storage, thereby facilitating fluid and electrolyte absorption. Colonic motility is modulated by myogenic, hormonal, and neural influences.   There is evidence that patients with diverticular disease manifest exaggerated contractile responses to feeding and hormonal stimuli.  Resting pressures are usually normal, however. These abnormal muscular contractions are believed to cause colonic smooth muscle hypertrophy, a characteristic of diverticular disease.

The possible role of dietary fiber in the development of diverticula is best explained by effects on colonic diameter and stool consistency. It has been postulated that colonic segments with bulky fecal contents and large luminal diameters are less likely to exhibit exaggerated segmentation. Low-fiber diets are associated with a narrowed colon filled with small, hardened feces; segmentation is enhanced, and high luminal pressures tend to develop. Although this concept has been widely disseminated, definitive evidence for a causal relationship between low dietary fiber and the development of diverticular disease does not exist. 31^,  39 Nonetheless, high-residue diets are in widespread use in the management of diverticular disease. Whether such therapy has a significant influence on the natural history of diverticular disease is unclear.

Anatomic Features. Diverticula tend to develop at specific points in the circumference of the colon. This localization is determined, in part, by the anatomic relationship between the colonic musculature and its nutrient blood supply. Diverticula form at so-called weak points where the nutrient blood vessels (vasa recta) penetrate the circular muscle layer en route to the mucosa. These perforating vessels tend to penetrate the colonic wall along the mesenteric border of the two antimesenteric taeniae. The gaps in the circular muscle layer where the vasa recta penetrate constitute points of potential weakness through which the mucosa and submucosa can herniate, forming diverticula. Diverticula, therefore, are usually located between the single mesenteric taenia and either of the two antimesenteric taeniae. Less commonly, diverticula form in the area between the antimesenteric taeniae. Although also consisting of mucosal herniation through the muscular layers of the colonic wall, these diverticula tend to be less prominent. In many instances the mucosal herniation does not quite extend to the serosa, causing these to be referred to as intramural diverticula.

The distribution of diverticula throughout the colon also tends to follow a pattern, but with considerable individual variation. The overwhelming majority of diverticula occur in the descending and sigmoid colon. It is estimated that 90% to 95% of patients with diverticulosis will have involvement of the sigmoid colon.  Approximately 65% of patients will have disease limited to the sigmoid colon alone.   Conversely, only a small number of patients (2% to 10%) will have disease confined to the right colon.   Solitary diverticula occur most commonly in the cecum.

NATURAL HISTORY

 

After the first episode of diverticulitis, approximately one third of patients will sustain a second attack, usually within 3 to 5 years.   Another 30% to 40% will suffer from intermittent symptoms of discomfort and crampy abdominal pain, without requiring hospitalization. The remainder can be expected to remain symptom free. The prognosis is worse after a second attack, with only 10% of patients remaining symptom free. The morbidity and the mortality from recurrent attacks are also higher than that associated with an initial episode. Complications such as abscess formation or fistulization develop in approximately 20% of patients after a single attack of diverticulitis, while the complication rate approaches 60% in patients who have had previous episodes.

 

             

 

 

 

Because diverticulosis is an acquired disease, the incidence of which clearly increases with age, it would seem logical that the number and size of diverticula would also increase with time. However, only 30% of patients demonstrate radiologic evidence of progression of their disease, either in the form of an increased number of diverticula or involvement of other segments of the colon. Progression of disease after resection of involved colon is also unusual, occurring in less than 10% to 15% of patients.  video   video2   video3   video4

 

 

CROHN’S DISEASE

 

Crohn‘s disease is a chronic, nonspecific inflammatory disease of the gastrointestinal tract of unknown etiology. It involves mainly the ileum and large intestine, most often producing symptoms of obstruction or localized perforation with fistula. Both medical and surgical treatments are palliative. Nonetheless, operative excision provides effective symptomatic relief and produces reasonable long-term benefit.

Epidemiology

Crohn’s disease is a chronic, idiopathic inflammatory disease with a propensity to affect the distal ileum, although any part of the alimentary tract can be involved. Recent estimates of the incidence of Crohn’s disease in the United States have ranged from 3.6 to 8.8 per 100,000. 34 A dramatic increase in incidence in the United States was observed to occur from the mid-1950s through the early 1970s. Incidence rates have been stable since the 1980s. Substantial regional variations in incidence have been observed, with the highest incidences reported to exist in northern latitudes. The incidence of Crohn’s disease varies among ethnic groups within the same geographic region. For example, members of the East European Ashkenazi Jewish population are at two- to fourfold higher risk of developing Crohn’s disease than are members of other populations living in the same location.

Most studies suggest that Crohn’s disease is slightly more prevalent in females than in males. The median age at which patients are diagnosed with Crohn’s disease is approximately 30 years; however, age of diagnosis can range from early childhood through the entire life span.

Both genetic and environmental factors appear to influence the risk for developing Crohn’s disease. The relative risk among first-degree relatives of patients with Crohn’s disease is 14 to 15 times higher than that of the general population. Approximately 1 of 5 patients with Crohn’s disease will report having at least one affected relative. The concordance rate among monozygotic twins is as high as 67%; however, Crohn’s disease is not associated with simple mendelian inheritance patterns. Although there is a tendency within families for either ulcerative colitis or Crohn’s disease to be present exclusively, mixed kindreds also occur, suggesting the presence of some shared genetic traits as a basis for both diseases.

Higher socioeconomic status is associated with an increased risk of Crohn’s disease. Most studies have found breast-feeding to be protective against the development of Crohn’s disease. Crohn’s disease is more prevalent among smokers. Furthermore, smoking is associated with the increased risk for both the need for surgery and the risk of relapse after surgery for Crohn’s disease.

Crohn’s disease is characterized by sustained inflammation. Whether this inflammation represents an appropriate response to a yet unrecognized pathogen or an inappropriate response to a normally innocuous stimulus is unknown. Various hypotheses on the roles of environmental and genetic factors in the pathogenesis of Crohn’s disease have been proposed.

Many infectious agents have been suggested to be the causative organism of Crohn’s disease. Candidate organisms have included Chlamydia, Listeria monocytogenes, Pseudomonas species, reovirus, Mycobacterium paratuberculosis, and many others. There is no conclusive evidence that any of these organisms is the causative agent.

Studies using animal models suggest that in a genetically susceptible host, nonpathogenic, commensal enteric flora are sufficient to induce a chronic inflammatory response resembling that associated with Crohn’s disease. In these models, the sustained intestinal inflammation is the result of either abnormal epithelial barrier function or immune dysregulation. Poor barrier function is hypothesized to permit inappropriate exposure of lamina propria lymphocytes to antigenic stimuli derived from the intestinal lumen. In addition, a variety of defects in immune regulatory mechanisms, e.g., overresponsiveness of mucosal T cells to enteric flora-derived antigens, can lead to defective immune tolerance and sustained inflammation.

Specific genetic defects associated with Crohn’s disease in human patients are beginning to be defined. For example, the presence of a locus on chromosome 16 (the so-called IBD1 locus) has been linked to Crohn’s disease. The IBD1 locus has been identified as the NOD2 gene. 35,36 Persons with allelic variants on both chromosomes have a 40-fold relative risk of Crohn’s disease when compared to those without variant NOD2 genes. The relevance of this gene to the pathogenesis of Crohn’s disease is biologically plausible, because the protein product of the NOD2 gene mediates the innate immune response to microbial pathogens.

Although the pathologic hallmark of Crohn’s disease is focal, transmural inflammation of the intestine, a spectrum of pathologic lesions can be present. The earliest lesion characteristic of Crohn’s disease is the aphthous ulcer. These superficial ulcers are up to 3 mm in diameter and are surrounded by a halo of erythema. In the small intestine, aphthous ulcers typically arise over lymphoid aggregates. Granulomas are highly characteristic of Crohn’s disease and are reported to be present in up to 70% of intestinal specimens obtained during surgical resection. These granulomas are noncaseating and can be found in both areas of active disease and apparently normal intestine, in any layer of the bowel wall, and in mesenteric lymph nodes.

As disease progresses, aphthae coalesce into larger, stellate-shaped ulcers. Linear or serpiginous ulcers may form when multiple ulcers fuse in a direction parallel to the longitudinal axis of the intestine. With transverse coalescence of ulcers, a cobblestone appearance of the mucosa may arise.

With advanced disease, inflammation can be transmural. Serosal involvement results in adhesion of the inflamed bowel to other loops of bowel or other adjacent organs. Transmural inflammation also can result in fibrosis, with stricture formation, intra-abdominal abscesses, fistulas, and, rarely, free perforation. Inflammation in Crohn’s disease can affect discontinuous portions of intestine: so-called “skip lesions” that are separated by intervening normal-appearing intestine.

A feature of Crohn’s disease that is grossly evident and helpful in identifying affected segments of intestine during surgery is the presence of fat wrapping (Fig. 27-17). This finding is virtually pathognomonic of Crohn’s disease. It is the encroachment of mesenteric fat onto the serosal surface of the bowel. The presence of fat wrapping correlates well with the presence of underlying acute and chronic inflammation.

 

ETIOLOGY

No specific etiology of the disease has been identified. There are two main schools of investigation: the microbiologic and the immunologic. Microbiologists have long sought a specific micro-organism that might be the cause of the disease; however, none has yet been identified. Recent reports of the isolation of Mycobacterium paratuberculosis from segments of bowel affected with Crohn‘s disease excited interest, but this organism as a specific etiology for the disease has yet to be proved. Also, no virus has been identified as an etiologic agent.

An immunologic origin of the disease has also been sought. No doubt an immunologic response to the condition does exist. Some have postulated that a childhood sensitization to milk impairs mucosal integrity and allows bacteria or bacteriologic products to enter the body. A cellular and humoral immune response to these products then ensues. The ileocolic epithelium, in particular, may be the target of a necrotizing immune response, with ensuing ulceration, tissue destruction, and the clinical appearance of the disease. Although an immunologic response certainly plays a role in the pathogenesis of the condition, its role as an etiologic agent is still unclear.

Other data suggest that environmental factors have an etiologic role in the disease. The disease is more common among persons living in temperate climates than among those living in tropical climates. Smoking may exert a stimulating effect on the disease; many patients with Crohn’s disease are heavy smokers. Spouses of persons with Crohn‘s disease have a higher incidence of the disease than persons in the general population. Although these data suggest that environmental factors have a role, no specific environmental factor has been identified.

 

SYMPTOMS

The most common symptoms of Crohn‘s disease are those from the intestinal lesions, with abdominal pain, especially of a cramping nature, topping the list. Diarrhea is frequent. The stools may contain blood, although they often do not. Patients experience abdominal distention or flatulence and sometimes nausea and vomiting. Eating becomes difficult, because it induces symptoms. Patients therefore decrease their food intake and lose weight. Should fistulas develop, the pain and discharge of intestinal content at the site of the fistulas to the skin or in the perianal area produce localized symptoms in these areas. Systemic responses include fever and malaise; localized pain and discomfort are related to the sites of extraintestinal involvement in the skin, eyes, and joints.

The course of the disease is one of exacerbations and remissions, but as the lesions mature and complications develop, the symptoms continue unabated and the disease becomes relentlessly progressive. About 70% of patients eventually come to operation, in spite of spontaneous remissions and medical or dietary therapy.

DIAGNOSIS

Diagnosis is based on the history, physical findings, and appropriate laboratory tests. The physical findings include the palpation of the thickened bowel wall or adjacent inflammatory response or abscesses in the abdomen. Hyperactive bowel tones are heard using auscultation, and peristaltic rushes in the small intestine may even be seen through a thin abdominal wall. Abdominal distention occurs. Fistulas are apparent, and probes and catheters can be passed through the cutaneous openings and into the lumen of the bowel through the tracts. On inspection, the perianal skin appears bluish, and perianal fissures, abscesses, and fistulas can be identified.

Proctoscopy often reveals the characteristic rectal aphthous ulcer with surrounding normal-appearing mucosa. With progressive and extensive involvement, the ulcerations involve more and more of the lumen of the bowel, with diminishing isolated segments of normal mucosa remaining. Anoscopy can show perianal abscesses, perianal fistulas, and even rectovaginal fistulas. Colonoscopy delineates the extent of the lesions in the large intestine. Sometimes the colonoscope can be passed through the colon and into the ileum to identify the ileal lesions of the disease. The hallmarks of Crohn’s disease are the discontinuous and asymmetrical nature of the endoscopic findings. Biopsies taken during endoscopy show chronic inflammation and sometimes granulomas.

Roentgenographic examination of the gastrointestinal tract using BaSO ₄  reveals the ulcerating lesions scattered in a segmental, irregular pattern along the wall of the involved intestine, producing irregular areas of ulceration, luminal narrowing, and thickened bowel wall (Fig. 31–17 . Proximal dilatation of the bowel accompanies obstructing lesions. Long lengths of narrowed terminal ileum may reduce the caliber of the lumen to the size of a string. Areas of dilatation may alternate with areas of constriction. The cobblestone appearance of the mucosa may be apparent, as may the rake ulcers. Fissures, fistulas, and perienteric abscesses may be found. Computed axial tomography may help delineate thickened bowel, perienteric abscesses, and perforations. In toxic megacolon, the transverse colon is greatly dilated and the bowel wall is thickened. A mass accompanying a narrowed or ulcerated area suggests cancer. Free air in the abdomen is present with free perforation.

The differential diagnosis includes both specific and nonspecific causes of intestinal inflammation. Specific microbiologic diseases that may be confused with Crohn‘s disease include bacterial inflammations such as those caused by salmonella and shigella, typhoid fever, intestinal tuberculosis, and protozoan infections such as amebiasis. Appropriate cultures and biopsies reveal the causative organisms in these conditions and rule them out. In regard to nonspecific intestinal inflammation, chronic ulcerative colitis can usually be differentiated from Crohn’s disease. Although ulcerative colitis involves the mucosa of the large intestine, it does not extend deep into the wall of the bowel, as does Crohn‘s disease. Ulcerative colitis nearly always involves the rectum most severely, with lessening inflammation from the rectum to the ileocolic area. In contrast, Crohn’s disease may be worse on the right side of the colon than on the left side, sometimes sparing the rectum. Ulcerative colitis also shows continuous involvement from rectum to proximal segments, whereas Crohn‘s disease shows segmental lesions. Although nonspecific, so-called backwash ileitis may be present in ulcerative colitis, ileal and small intestinal involvement suggests Crohn’s disease. Bleeding is a more common symptom in ulcerative colitis and is less common in Crohn‘s disease. Perianal involvement and rectovaginal fistulas are unusual in ulcerative colitis but are more common in Crohn’s disease. In most instances, the two diseases can be clearly separated, but a subgroup of 5% to 10% of all patients with chronic nonspecific inflammatory bowel disease cannot be clearly classified as having ulcerative colitis or Crohn‘s disease. These patients are usually given a diagnosis of “indeterminate” colitis. The true diagnosis often becomes apparent as the patients are followed through the years.

Endoscopic view

 

 

Crohn’s disease, symptom of “roadway”. Endoscopy examination

 

 

Crohn’s disease. Hyperemia and deep cracks of mucus membrane of colon, ulcers, symptom of “roadway”

 

 

 

 

Stricture ascending part of the colon. Crohn’s disease. Irrigogram.

 

 

 

Crohn’s disease.  Multiple fistulas.

 

 

Acute distal ileitis may be a manifestation of early Crohn’s disease, but it also may be unrelated, such as when it is caused by a bacteriologic agent such as Campylobacter or Yersinia. Patients usually present in a manner similar to patients with acute appendicitis. They have a sudden onset of right lower quadrant pain, nausea, vomiting, and fever, with tenderness over the area of involvement. The diagnosis is made at operation by identifying an acutely inflamed segment of terminal ileum. No biopsy or resection should be done. The condition almost always subsides spontaneously, and the segment should not be excised. If the cecum is not involved, the appendix should be removed to prevent subsequent bouts of right lower quadrant inflammation from being confused with appendicitis.

THERAPY

Medical and Dietary Therapy

Medical therapy consists of sulfasalazine, 5-aminosalicylic acid, corticosteroids, antibiotics such as metronidazole and ampicillin, and immunosuppressive agents such as azathioprine and cyclosporine. Because no specific etiology has been identified for Crohn‘s disease, the treatments are also nonspecific. They suppress inflammation and improve symptoms but are not curative.

Manipulations of the diet ordinarily have little effect on the progress of Crohn’s disease. However, complete abstinence of oral intake with total parenteral nutrition may lead to temporary remission of symptoms in some patients with Crohn‘s disease. Sometimes enteroenteric or enterocutaneous fistulas close. Few long-term benefits of total parenteral nutrition have been achieved, however. When oral intake is resumed, the patients usually have recurring difficulty, and the symptoms of the disease return.

Pharmacologic agents used to treat Crohn’s disease include antibiotics, aminosalicylates, corticosteroids, and immunomodulators. Antibiotics have an adjunctive role in the treatment of infectious complications associated with Crohn’s disease. They are also used to treat patients with perianal disease, enterocutaneous fistulas, and active colonic disease.

Most studies have shown sulfasalazine, the parent compound of all aminosalicylates used to treat Crohn’s disease, to be superior to placebo in inducing disease remission. Its efficacy in the maintenance of remission is less clear. Aminosalicylates are associated with minimal toxicity and are available in a variety of formulations that allow for their delivery to specific regions of the alimentary tract.

Orally administered glucocorticoids are used to treat patients with mildly to moderately severe disease that does not respond to aminosalicylates. Patients with severe active disease usually require intravenous administration of glucocorticoids. Although glucocorticoids are effective in inducing remission, they are ineffective in preventing relapse and their adverse side-effect profile makes long-term use hazardous. Therefore, they should be tapered once remission is achieved. Some patients are unable to undergo glucocorticoid tapering without suffering recurrence of symptoms. Such patients are said to have glucocorticoid dependence and are candidates for therapy with glucocorticoid-sparing immune modulators.

The thiopurine antimetabolites azathioprine and 6-mercaptopurine have demonstrated efficacy in inducing remission, in maintaining remission, and in allowing for glucocorticoid tapering in glucocorticoid-dependent patients. There is also some evidence that they decrease the risk of relapse after intestinal resection for Crohn’s disease. These agents are relatively safe, but can induce bone marrow suppression and promote infectious complications. For patients who do not respond to the thiopurines, methotrexate is an alternative. There is little role for cyclosporine in Crohn’s disease; its efficacy/toxicity profile in this disease is poor.

Infliximab is a chimeric monoclonal anti–tumor-necrosis-factor antibody that has efficacy in inducing remission and in promoting closure of enterocutaneous fistulas. 37 Infliximab is generally well tolerated but should not be used in patients with ongoing septic processes, such as undrained intra-abdominal abscesses.

Surgical Therapy

Indications for Operation. Patients with Crohn’s disease are usually operated on because an intestinal complication of Crohn‘s disease mandates the operation. All in all, about 70% of patients with Crohn’s disease will come to operation. The most common complications leading to operation are recurrent intestinal obstruction, intestinal perforation with fistula formation and abscess, or a gastrointestinal bleeding. 2 Obstruction is usually partial and is seldom complete. With nasogastric suction and intravenous nutrition, the distended bowel usually decompresses, and bowel movements resume. Failure to achieve complete resolution or recurrence of obstructive symptoms with the resumption of oral feedings usually leads to operation. Perforation with fistula formation and resultant abdominal mass usually causes continuing pain, fever, malaise, and weight loss until operation can be accomplished. Perianal complications, such as abscess and fistula, commonly lead to operation. Bleeding, a less frequent cause of operation, is usually not massive, but it may be persistent and contribute to chronic anemia until the offending lesion or lesions can be resected. Patients with small intestinal Crohn‘s disease usually require operation for obstruction or perforation, whereas those with large intestinal Crohn’s are usually operated on for chronic debility and failure to respond to medical therapy.

Severe systemic symptoms, intractable medical therapy, and weight loss, especially with growth failure in children, can also lead to operation. Prepubertal and early pubertal patients experiencing growth failure from Crohn‘s can be expected to sustain catch-up and accelerated growth after resection. 16 Toxic megacolon and cancer of the small or large intestine are less common intestinal complications requiring operation. Extraintestinal complications in and of themselves seldom require intestinal operation, but they often contribute to the decision to operate. Most of the extraintestinal complications, with the exception of ankylosing spondylitis and the hepatic complications, subside with the excision of intestine grossly involved with Crohn’s disease.

Preoperative Preparation. The nutritional status of the patient is optimized before operation. This sometimes, but not often, requires parenteral caloric supplementation. Anemia is treated by blood transfusion. For patients currently on or recently receiving corticoid therapy, additional steroids— usually 100 mg. of hydrocortisone intravenously every 8 hours—are given to ensure an adequate supply during the operative stress. The bowels are cleansed with laxatives and enemas the day prior to operation. Alternatively, 4 liters of an electrolyte solution (GoLYTELY) can be given by mouth the night before operation. 36 Diet is restricted to clear liquids the day before operation.

The growth of enteric bacteria in patients having the laxative-enema preparation is suppressed by giving oral neomycin 0.5 gm. every 4 hours, and tetracycline, erythromycin, or metronidazole 250 mg. every 4 hours, for 18 hours prior to operation. When the GoLYTELY preparation is used, 2 gm. neomycin and 2 gm. metronidazole are given by mouth 12 hours and 8 hours before operation. With both preparations, cefazolin 0.5 gm. is given intravenously just prior to operation and is continued every 8 hours for two more doses.

General Principles of Operation. Because Crohn‘s disease involves nearly the entire gastrointestinal tract in most patients, total excision of the disease is not possible. Thus, surgical treatment is directed at the most severe areas of involvement, including those that account for the complications of obstruction, bleeding, or perforation.

The two main operative approaches are to excise the lesions or to bypass them. Currently, most surgeons advise excision rather than bypass. Bypass allows the diseased intestine to remain in place, where it can cause continuing symptoms, require treatment, and perhaps even develop malignancy. The risk of cancer in bypassed small and large intestine with Crohn’s disease is greater than the risk in healthy bowel. Excision is done with 3-cm. “disease-free” margins on both sides of the area of involvement. The disease-free margins are established by gross inspection. Most surgeons do not use microscopic confirmation of healthy borders. Although the authors have found that when borders are free of microscopic involvement there are fewer recurrences over the long term than when the border is involved, 37 others have not found a higher recurrence rate when histologic findings of Crohn‘s are present in the margins. Certainly, demanding microscopic borders that are free of disease may lead to excessively large resections and result in the short bowel syndrome. Patients with this syndrome do not have enough intestine remaining to digest and absorb their food properly.

After resection and anastomosis of the index segment (or segments) of intestine that has led to the operation, fistulas from the index segment to adjacent organs, such as the stomach, colon, duodenum, bladder, or vagina, can usually be closed by suture of the entrance of the fistula into the adjacent segment. Resection of the adjacent segment is seldom required, unless it is primarily involved with gross Crohn’s disease.

 

UNSPECIFIC ULCEROUS COLITIS

 

Ulcerative colitis, a diffuse inflammatory disease of the mucosal lining of the colon and rectum, is characterized by bloody diarrhea that exacerbates and abates without apparent cause. It is difficult to realize that a disease so devastating remains without an identified etiology or specific medical therapy. Total removal of the affected organs—the colon and rectum—provides a complete cure, but at a sacrifice, since patients so treated must learn to live with an external abdominal stoma (an ileostomy) for the remainder of their lives. Since the disease has its peak onset in early and middle adulthood, this represents a long time span for most patients. Fortunately, new surgical alternatives have eliminated the need for a permanent ileostomy without sacrificing definitive treatment of the disease.

 

ETIOLOGY

The etiology of ulcerative colitis remains unknown despite intensive work by many investigators. The examination of bacterial and viral agents continues to be an area of great activity. Whether the infectious agents are more likely to be triggers of disease or perpetuators of disease is of great controversy. To be a trigger, an infectious agent would have to act by initiation or reactivation. Agents could initiate an autoimmune response by altering antigens, affecting molecular immunity, or increasing immune responsiveness. The microbial agent might also trigger the pathologic response by increasing mucosal permeability or stimulating epithelial injury or localized ischemia. The microbial agent could reactivate the inflammatory process directly, by secondary infection, or by the release of toxins. Evidence for microbial agents as triggers in inflammatory bowel disease is only indirect.

Psychologic factors have long been thought to have a critical role in exacerbations of the disease.   It is now clear that patients with ulcerative colitis have no unusual predisposing factors when compared with matched controls.  Moreover, colectomy is usually followed by a marked improvement in pre-existing morbid psychologic states such as depression or social estrangement. Psychosomatic factors most likely only facilitate the colonic mucosal reaction to another as yet unidentified causative agent.

Another area of great interest has been that of cytokines and immunoregulatory molecules involved in the control of the immune response. 61 The production of interferon during inflammation could have a significant role in the differentiation of mature memory and effector cells within the intestine. Specific activities of interleukins that are potentially relevant to inflammatory bowel disease have been identified. Most important of these may be interleukin-1 (IL-1), which activates T and B lymphocytes as well as macrophages and neutrophils. IL-1 stimulates production of eicosanoids, cytokines, growth factors, and destructive enzymes; increases adhesion of neutrophils and monocytes to endothelial cells; induces acute-phase response as well as fever, anorexia, and sleep; and stimulates collagen production and thus fibrosis. IL-1 has been shown to be elevated in ulcerative colitis as well as in experimental models of colitis. The increase in IL-1 levels seems to correlate with severity of disease. Alterations in IL-2, IL-6, IL-8, and interferon-gamma have been identified in tissues from patients with ulcerative colitis. The production of interferon during inflammation could play a significant role in the differentiation of mature memory and effector cells within the intestine. Tumor necrosis factor may also be particularly important in the activation of mesenchymal cells but has not been fully evaluated in ulcerative colitis. Thus, it appears that cytokines are integrally involved in the pathogenesis of inflammatory bowel disease with both immunoregulatory and proinflammatory properties.

 

PATHOLOGY

Ulcerative colitis is, for the most part, a disease confined to the mucosal and submucosal layers of the colonic wall, progressing from mucosal edema and lipemia to vascular congestion, superficial ulcers, increased cellular infiltration of the lamina propria, and cyst abscesses beginning in the rectum and advancing proximally to involve the entire colon. In 10% of patients, the terminal ileum may show mild inflammation and dilation, a process that has been called backwash ileitis. On gross inspection, the colonic mucosa demonstrates healed granular superficial ulcers superimposed on a friable and thickened mucosa with increased vascularity. Patients may also demonstrate superficial fissures and small and regular pseudopolyps. This is in contradistinction to the transmural inflammatory changes found in Crohn’s disease of the colon, in which all layers may be involved in a granulomatous inflammatory process. The pathologic changes observed in ulcerative colitis, however, are nonspecific and can be seen in shigellosis, amebiasis, and gonorrheal colitis.

 

 

CLINICAL MANIFESTATIONS

The initial presentation of ulcerative colitis can take many forms. Bloody diarrhea is the most common early symptom. Occasionally, extraintestinal manifestations, including arthritis, iritis, hepatic dysfunction, and skin lesions, may be paramount. The disease presents as a chronic, relatively low-grade illness in most patients. In a small number of patients (15%), it has an acute and catastrophic fulminating course. Such patients present with frequent bloody bowel movements (up to 30 per day), high fever, and abdominal pain. The disease therefore has a wide spectrum of clinical manifestations, ranging from a mild diarrheal illness to an overwhelming life-threatening event of short duration that demands immediate medical attention.

Onset of the disease occurs in patients less than 15 years of age in approximately 15% of cases, and presentation in patients over 40 years of age is not uncommon. The incidence of ulcerative colitis is 3.5 to 6.5 per 100,000 population, and the prevalence is 60 per 100,000. A slight female predominance has been reported.

Physical findings are directly related to the duration and presentation of the disease. Weight loss and pallor are usually present. In the active phase, the abdomen, in the region of the colon, is usually tender to palpation. There may be signs of an acute abdomen accompanied by fever and decreased bowel sounds. This is especially true during acute attacks or in the fulminating form of the disease. Abdominal distention is unusual, except in patients who have toxic megacolon, in which case the patient is usually febrile and has signs of an acute abdomen. The perianal area may be excoriated from the numerous wipings associated with bowel movements. There may be evidence of perianal inflammation in the form of a fissure, abscess, or fistula in ano, although the last is more common in Crohn‘s disease. Rectal examination is almost always painful and, in the presence of perianal inflammation, should be done with gentle care. Examination of the integument, tongue, joints, and eyes is important, since the presence of disease in these areas suggests ulcerative colitis as a likely cause of the diarrheal illness.

 

 

The contracted appearance of this colon, as viewed
by barium roentgenogram, is typical of advanced ulcerative colitis in its chronic phase.

 

Proctosigmoidoscopy is a helpful and specific diagnostic aid, since ulcerative colitis involves the distal colon and rectum in 90% to 95% of cases. In fact, the mucosa of both the rectum and the sigmoid colon is usually erythematous and granular and bleeds easily when touched by the endoscope or rubbed with a cotton swab. Normal colonic vascular markings may be absent, or the mucosa may be hyperemic; in the disease-bearing mucosa, superficial (less than 2 mm.) mucosal alterations are seen. The intercolonic haustra are thick and blunted. Cobblestoning and deep linear ulceration, which are common endoscopic findings in Crohn’s disease, are unusual in ulcerative colitis. In advanced disease, ulcers may be present, surrounded by hyperplastic areas of granulation tissue and edematous mucosa, which may assume a polypoid appearance (pseudopolyps). Mucosal bridging is also commonly found. In chronic advanced disease, the lumen of the rectosigmoid may be remarkably contracted. The use of flexible sigmoidoscopy has improved diagnostic accuracy and patient acceptance. Colonoscopic examination is of value in determining the extent and activity of the disease. Unless a distinct granuloma is identified, endoscopic biopsies are of little value in differentiating ulcerative colitis from Crohn‘s colitis.

Although recent studies suggest that previous reports may have overestimated the risk of cancer in the adult population with ulcerative colitis, patients with this disease still appear to be confronted with at least a 10% to 20% likelihood of developing carcinoma within 20 years of the diagnosis of ulcerative colitis. 100 Adenocarcinoma in association with ulcerative colitis is multicentric in 15% of patients. In addition, the cancers tend to be flatter and perhaps more infiltrating. These tumors are more evenly distributed throughout the colon, with approximately 50% being found proximal to the splenic flexure. Carcinoma in association with ulcerative colitis is more difficult to diagnose by history and physical examination, stool guaiac testing, and radiographic studies. The likelihood of carcinoma in patients with ulcerative colitis appears to relate to both the extent of colonic involvement and the duration of disease. Although it is generally accepted that patients with extensive total ulcerative colitis are at increased risk of developing carcinoma, the question of what constitutes extensive colitis is still not fully resolved. In addition, the assessment is variable if judged radiographically or colonoscopically. The evidence that patients with left-sided ulcerative colitis, by any criteria, are at increased risk when compared with the general population—which carries a 4% to 6% likelihood of developing colorectal carcinoma, with three fourths of these cancers occurring on the left side—is far from overwhelming. The likelihood of cancer may be related to duration of activity and age of onset, although this has not been clearly established. Although it was held for some time that the carcinoma associated with ulcerative colitis was more aggressive than that in the general population, recent studies have demonstrated that the natural evolution of the cancer is likely the same in both groups.

 

                 

 

Unspecific ulcerative colitis

 

 

 

Unspecific ulcerative colitis. Malignization

 

 

 

Unspecific ulcerative colitis. Pseuopoliposis

 

 

 

Rectal biopsies have also been advocated to assess the presence or absence of dysplasia. Morson and Pang 71 advocate a surveillance program of rectal biopsy to assess the point at which a patient becomes at high risk for colonic cancer. When dysplasia of the rectal mucosa is identified, colectomy has been advocated. Other investigators in this field have found the test less useful, with false-negative results of 20% to 40% and false-positive results of 30% to 40%. 90 Colonoscopy may improve the accuracy of surveillance; however, random biopsies have a very low yield because of the immense sampling problem. Between 20 and 25 equally spaced biopsies are required on a 10-cm. length of colon to reasonably detect a patch of dysplasia 2 cm. in diameter. Moreover, the endoscopic appearances of both dysplasia and carcinoma in ulcerative colitis remaiearly undocumented. The biopsy of target lesions, that is, any lesion that cannot be reasonably accepted as part of the chronic disease state, is recommended. In addition, the end-point of surveillance remains controversial. Many gastroenterologists recommend colectomy only in the presence of high-grade dysplasia, a dysplasia-associated mass lesion, or a frank carcinoma. Unfortunately, the presence of dysplasia, whether low-grade or high-grade, can give rise directly to an invasive carcinoma, and all large centers have had patients under surveillance who developed and died of colorectal carcinoma. Some evidence suggests that even low-grade dysplasia unassociated with severe inflammation, if it is unequivocal, should prompt colectomy. To date, no prospective study has clearly demonstrated that surveillance lowers the mortality from colorectal cancer in association with ulcerative colitis,  although a large review from St. Marks suggested an overall 5-year survival of 87% in those patients who underwent surveillance and 55% in those who did not.

A plain abdominal film may reveal a variant of the disease called toxic megacolon, in which there may be free air within the peritoneal cavity from perforation of the colon. A more common sign is a remarkable dilation of the transverse colon.

Barium enema examination, usually with air contrast, can be performed safely in most patients and is extremely helpful in identifying the extent and severity of the disease. Barium roentgenographic signs include loss of haustral markings and irregularities of the colon wall, which represent small ulcerations. These are well demonstrated in picture, which contrasts the appearance of the left side of the splenic flexure and that of the right. As the disease progresses, pseudopolyps become a prominent roentgenographic sign. In advanced disease, the colon assumes the appearance of a rigid contracted tube. The barium roentgenogram, although useful, should be avoided in the presence of toxic megacolon, since it may exacerbate the colitis. When diarrhea is not present, a liquid diet for 3 days prior to examination is recommended. Barium roentgenogram should be omitted when the clinical signs of toxic megacolon are present. Upper gastrointestinal contrast studies are also indicated in most patients to exclude Crohn’s disease.

The aforementioned clinical manifestations and simple diagnostic tests usually help identify the presence of ulcerative colitis. It is necessary, however, to obtain stool smears and cultures to exclude colitis due to viruses, Chlamydia, bacterial pathogens, and parasites. Particularly important and difficult to exclude are pseudomembranous colitis, the proctocolitis seen increasingly in homosexual males, and traveler‘s diarrhea. Cello and Meyer 12 provided a useful schema for distinguishing ulcerative colitis from granulomatous colitis.  Note, however, the low frequency of discriminating clinical characteristics, except for associated small bowel disease or skip areas within the colon, when the etiology is Crohn’s disease.

The strong association of cancer of the colon with ulcerative colitis bears further emphasis. 115 For example, 40% of patients with total colonic involvement may die of cancer if they survive their disease and the colon is left in place. 62 Three percent of children with ulcerative colitis have cancer of the colon at 10 years; 20% develop cancer during each ensuing decade. 20 With the availability of far more acceptable surgical alternatives to proctocolectomy and ileostomy, it is hoped that patients will obtain definitive treatment for the disease well before they enter the phase of accelerating cancer risk. These data support close medical management for such patients and surgical intervention, on this basis alone, when chronicity is well established.

The extracolonic manifestations of ulcerative colitis can be categorized as the colitis group, the pathophysiologic group, and the miscellaneous group of disorders. The colitis group of extracolonic manifestations generally parallels the activity of the underlying bowel disease, being present and most active when the colitis is active and usually subsiding when the colitis goes into remission induced by medical therapy, by surgical intervention, or spontaneously. It appears most likely that these extracolonic disorders represent antigen-antibody immune complex disorders. Ocular manifestations are common in ulcerative colitis and include conjunctivitis, iritis, and choroiditis. These are closely related to disease activity and respond to steroid therapy. More severe and rare eye diseases, including ulcerative panophthalmitis, are more difficult to treat, even with high-dose steroid suppression. Articular disorders, including peripheral joint disease, arthralgias, swelling, pain, and redness with migratory involvement, usually parallel the intensity of the colitis and respond to medical or surgical treatment. The joints of the lower extremities are most frequently involved. Fortunately, permanent deformity of these joints is very uncommon. A certain percentage of patients go on to develop clear evidence of rheumatoid arthritis even after colectomy. Ankylosing spondylitis and sacroiliitis, in contrast, can cause permanent fixation of the spine and need to be treated aggressively. Bone involvement specific to the axial skeleton is less closely related to the severity of the inflammatory state of the colon and, in fact, may precede frank evidence of ulcerative colitis. Patients with ulcerative colitis frequently experience dermatologic disorders, including erythema nodosum and pyoderma gangrenosum. Although these difficult problems resolve after colectomy in most patients, in others, they may precede the colonic disease or may not become manifest until after proctocolectomy has been performed.

Pathophysiologic disorders are more often seen in Crohn‘s disease than in ulcerative colitis, since in ulcerative colitis, the normal physiology of the terminal ileum is not disturbed. Liver disease is common in patients with both ulcerative colitis and Crohn’s disease. Nonspecific inflammation and fatty metamorphosis manifested by mild increases in the serum transaminase values are common in ulcerative colitis. Pruritus and elevation of the alkaline phosphatase are commonly associated with the pericholangitis that occasionally accompanies ulcerative colitis. The most dreaded complication, sclerosing cholangitis, presents with pruritus, alkaline phosphatase elevation, right upper quadrant pain and tenderness, and jaundice. The diagnosis is most often made by endoscopic retrograde cholangiopancreatography or transhepatic cholangiography. It has been estimated that 50% of patients who present with sclerosing cholangitis already have or will develop frank ulcerative colitis. Controversy surrounds the treatment of this disorder. Whereas some patients respond to colectomy, many others show progression of their disease even after colon resection. Surgical drainage, internal stent placement, antibiotics, and ultimately liver transplantation have all been reported to be of value in the treatment of symptomatic sclerosing cholangitis. Cholangiocarcinomas have also been reported in patients with ulcerative colitis, usually after many years of sclerosing cholangitis.

MEDICAL MANAGEMENT

The outcome of an acute episode of ulcerative colitis relates to the severity of the disease as manifested by systemic symptoms. Duration of the disease and extent of involvement of the colon do not appear to be determinants of survival if ulcerative proctitis is excluded from consideration. Those who present with advanced signs of acute illness require hospitalization and supportive, as well as specific, therapy for associated metabolic and hematologic derangements. Because of the massive fluid and electrolyte loss per rectum, such patients often present with metabolic acidosis, contracted extravascular volume, and prerenal azotemia. The serum potassium level is usually low because of excessive loss in stool and urine. Intravenous administration of balanced salt solutions in amounts sufficient to replace these losses is an initial step in management. Patients with long-standing disease may have lost considerable protein and probably are in a depleted nutritional state. The precise role of specialized nutritional support in ulcerative colitis and, in particular, of total parenteral nutrition is unclear. Despite early enthusiasm, total parenteral nutrition does not appear to have a specialized therapeutic role in this disease. Total parenteral nutrition improves the overall nutritional state of patients with ulcerative colitis and may reverse growth retardation in children, but it certainly does not replace conventional medical treatment or prevent or delay colectomy. In fact, in patients with severe acute colitis, it may be impossible to attain a positive nitrogen balance while the colon is still in place.

Corticosteroids and immunosuppressive agents have both been demonstrated to be effective in the management of ulcerative colitis. Both agents, however, are capable of producing significant side effects. In general, corticosteroids have been more readily accepted by the medical community as therapeutic agents and remain the mainstay of therapy in acute attacks. Between 40 and 60 mg. of prednisone in a single daily dose is effective in inducing remission. 110 Rectal steroids have been shown to be effective in left colon disease or proctitis and may have therapeutic efficacy in universal colitis as well, perhaps because approximately 30% of the steroid given rectally is absorbed into the systemic circulation. In an attempt to avoid systemic effects of steroid enemas, tixocortol pivalate was synthesized by adding a thiol ester group at position 21 on the hydrocortisone molecule. In trials, this agent has been useful for treating patients with left-sided colitis and has resulted in a reduction in systemic steroid side effects. The controversy over intravenous steroids versus intravenous adrenocorticotropic hormone (ACTH) has now been resolved by a randomized trial that revealed a similar response to equipotent doses of either hormone. 49 A recent study suggests that ACTH may be more effective in patients not previously treated with corticosteroids, whereas corticosteroids appear to be preferable for patients already receiving steroid therapy. 68 A steroid-induced remission is not more likely to exacerbate than a spontaneous remission, and an ACTH-induced remission is not more likely to exacerbate than a corticosteroid-induced remission. The usual recommended doses are 300 mg. of hydrocortisone or 40 units of ACTH per day. Occasionally, massive doses of steroids (over 1 gm. per day) are required. The usual response is rapid, and acute signs of inflammation subside within a few days. The optimal duration of intravenous steroid therapy is 5 to 7 days, although this may be extended in patients supported nutritionally with total parenteral nutrition. Proctoscopic examination is useful in following response to therapy. There is still controversy as to whether maintenance steroid thereby reduces recurrence of the disease. Although maintenance steroids may be useful in controlling symptoms of patients with continuing activity, maintenance therapy with low-dose corticosteroids for patients with inactive disease has not been demonstrated to prevent relapse. 59 Patients must be monitored carefully for the long-term adverse sequelae of corticosteroid use, including hypertension, hyperglycemia, cataracts, osteoporosis, and osteomalacia.

Sulfasalazine has enjoyed widespread use in the chronic phases of ulcerative colitis. Its mode of action is unknown. Sulfasalazine may exert this prophylactic effect by inhibiting mucosal prostaglandin synthesis, 49 although not all studies have supported this mechanism. 81 Whatever the mechanism of action, sulfasalazine appears to be associated with fewer exacerbations as assessed by controlled randomized trials. 21^,  108 The drug appears to be of lesser value in severe ulcerative colitis. Sulfasalazine is metabolized by bacteria to 5-aminosalicylic acid (5-ASA) and sulfapyridine. Dose-related side effects of sulfasalazine include nausea, vomiting, headache, and abdominal discomfort. Reversible hypospermia and infertility are observed in males. Hypersensitivity effects include fever, skin rash, agranulocytosis, and hemolytic anemia. Studies have indicated that the sulfapyridine produced by bacterial degradation of sulfasalazine is responsible for the majority of the side effects, whereas the 5-ASA component appears to be the effective moiety of the drug. Five-aminosalicylic acid is now available in this country for clinical use. In all studies to date, these compounds have been shown to be as efficacious as sulfasalazine in treating acute ulcerative colitis as well as in preventing relapse.

A third approach has been the use of immunosuppressive agents. Rosenberg and colleagues 88 concluded, based on a well-controlled study, that azathioprine allows reduction of the use of steroids in chronic cases but does not, in itself, control exacerbation of the disease. In a more recent controlled trial, however, Kirk and Lennard-Jones 54 demonstrated that clinical improvement may occur in about 25% of patients treated with a dose of azathioprine at 2 to 2.5 mg. per kg. Uncontrolled trials have demonstrated a favorable response to 6-mercaptopurine (6-MP) in 64% to 70% of patients with refractory ulcerative colitis. 81 Because these drugs do not produce a clinical response for several months, they have no role in the treatment of acute flares of ulcerative colitis. Cyclosporine (CS), which has a more rapid onset of action, has been advocated for the treatment of severe, refractory acute ulcerative colitis. Both uncontrolled trials and one controlled study suggest that high-dose CS is efficacious for severe ulcerative colitis. There is, however, significant theoretical risk of irreversible CS-associated nephropathy following treatment with high-dose CS. Severe infectious complications may also occur. 92 A trial of 6-MP or CS may be warranted when steroids and sulfasalazine have failed, when the disease is confined to the left side of the colon or rectum, when the patient is compliant, and when there is no absolute indication for immediate surgical therapy. 80 However, before prescribing these immunosuppressive agents, one must be fully familiar with the dosing, monitoring, toxicity, and possible induction of lymphoma or other malignancies associated with these drugs.

Although widely prescribed for both ulcerative colitis and Crohn‘s disease, metronidazole and other antibiotics have no proven value in the treatment of inflammatory bowel disease.

The major therapeutic problem between acute episodes is control of diarrhea and maintenance of nutrition. Diet therapy is no longer recommended, and patients are encouraged to eat a substantial diet of their choice. Milk products are to be avoided only if they cause problems such as increasing diarrhea or cramps (as they may in about half of patients with ulcerative colitis). The reason for this is not clear but relates to something specific in cow’s milk rather than to the lactase deficiency that exists in many patients with ulcerative colitis. Opiates such as codeine or paregoric should be avoided. Nocturnal diarrhea can be controlled by anticholinergics or diphenoxylate with atropine. The synthetic peripheral-acting opioid loperamide may be more effective than diphenoxylate in this situation and avoids the atropine side effect associated with this drug. 74 Stool bulk formers, such as psyllium, are also helpful. Finally, the importance of rest and peace of mind cannot be overemphasized. Patients are advised to remain at rest during episodes of exacerbation.

INDICATIONS FOR SURGICAL TREATMENT

Since total removal of the colon and rectum (proctocolectomy) cures ulcerative colitis, one might reasonably ask why all patients with established chronicity are not so treated. The incidence of surgical intervention appears to be related to the availability of skilled and knowledgeable gastrointestinal surgeons and enlightened physicians. For example, the clinic at Leeds offers surgical care to approximately half of its patient population, 38 whereas in another center the reported operative rate is below 10%. 35 There are several well-identified complications that require urgent operation for survival. 36 These include massive, unrelenting hemorrhage; toxic megacolon with impending or frank perforation; fulminating acute ulcerative colitis that is unresponsive to steroid therapy; obstruction from stricture; and suspicion or demonstration of colonic cancer. Surgical therapy is also recommended in children who fail to mature at an acceptable rate. The largest number of colectomies for ulcerative colitis are performed for less dramatic indications, as the disease enters an intractable chronic phase and becomes both a physical and a social burden to the patient.

Acute perforation occurs infrequently, with the incidence directly related to both the severity of the initial episode and the extent of the disease in the bowel. Although the overall incidence of perforation during a first attack is less than 4%, if it is severe, the incidence rises to 9.7%. If the total colon is involved, the perforation rate is 14.6%, and if the attack is both severe and involves the total colon, it increases to 19.2%. 37

Obstruction caused by benign stricture formation occurs in 11% of patients, 34% of these occurring in the rectum. 19 They usually follow submucosal fibrosis and occasionally mucosal hyperplasia. Although they do not usually cause acute obstruction, the lesions must be differentiated from carcinoma by biopsy or excision, and particular attention should be given to excluding Crohn‘s disease. Strictures caused by carcinoma are less common than those caused by benign disease and are more prone to perforate.

Massive hemorrhage secondary to ulcerative colitis is rare, occurring in less than 1% of patients. 37 Prompt surgical intervention is indicated after hemodynamic stabilization. More than 50% of patients with acute colonic bleeding have toxic megacolon, so one should be suspicious of the coexistence of the two complications. Uncontrollable hemorrhage from the entire colorectal mucosa may be the one clear indication for emergency proctocolectomy. If possible, the rectum should be spared for later mucosal proctectomy with ileoanal anastomosis.

Acute toxic megacolon can occur in both ulcerative colitis and Crohn’s disease. Its incidence is between 6% and 13% in patients with ulcerative colitis. 30 Patients usually present clinically with the onset of abdominal pain and severe diarrhea (greater than 10 stools per day), followed by abdominal distention and generalized tenderness. Once megacolon and toxicity develop, fever, leukocytosis, tachycardia, pallor, lethargy, and shock ensue. It is important to note that any of these manifestations can be masked by chronic steroid use and the generally poor nutritional condition of the patient. An abdominal radiograph usually shows dilation of the transverse and occasionally the sigmoid colon that is greater than 5 cm. and averages 9.2 cm.  Thickening and nodularity of the bowel wall due to mucosal inflammation are also noted. Caprilli and colleagues 10 reported abnormal gaseous distention of the small bowel in association with toxic megacolon; thus, this finding may be a useful predictor of its development in patients with severe colitis.

The morbidity and mortality for acute toxic megacolon remain high. Soyer and Aldrete 103 reported a series of 12 patients in which the incidence of postoperative sepsis was 50%, wound infection 58%, abscess of fistula 33%, and delayed wound healing 25%. Postoperative mortality ranges from 11% to 16%; for the subset of patients with perforation, mortality is 27% to 44%. 42^,  47 These data support the use of combined aggressive medical and surgical treatment of this disease.

Initial treatment for toxic megacolon includes intravenous fluid and electrolyte resuscitation, nasogastric suction, broad-spectrum antibiotics to include anaerobic and aerobic gram-negative coverage, and total parenteral nutrition to improve nutritional status. Proctoscopy may be helpful in determining the etiology of the attack, as may culture of the stool. Although the efficacy of steroids is still in question, 67 most patients presenting with toxic megacolon are already on steroid therapy and thus need stress doses of corticosteroids to prevent adrenal crisis. Most clinicians think that steroids help reduce the inflammation and may cool down an acute toxic episode in up to 50% of patients, although long-term remissions are not achieved. 40 Moreover, the short-term use of corticosteroids does not appear to increase surgical morbidity. Long-term use of larger doses, however, does increase the incidence of wound and septic complications. The authors agree with Fazio 30 that, provided the patient is stable, initial medical trial is warranted in order to make the operation elective rather than urgent. If no clear response is obtained within 24 to 48 hours, surgical therapy is warranted. Larger doses of steroids after initial medical failure probably will not benefit the patient and, as noted, may be deleterious. During medical therapy, serial blood counts, serum electrolyte levels, and abdominal roentgenograms should be closely monitored.

In the presence of acute toxic megacolon caused by ulcerative colitis, surgical therapy can be associated with a high operative morbidity and mortality. Block and colleagues 6 noted an overall mortality following emergency operation of 8.7%; 6.1% after total abdominal colectomy, and 14.7% after proctocolectomy. This suggests that more conservative surgical intervention is appropriate in the acute setting. Also, with the recent popularity of anal sphincter–sparing procedures, when operating for acute ulcerative colitis, one should weigh the possibility of subsequent surgical correction for continence. Specifically, leaving the rectum intact allows its use for subsequent surgical mucosal proctectomy and ileoanal anastomosis. When urgent colectomy is required, total abdominal colectomy, Brooke ileostomy, and Hartmann‘s pouch are appropriate. 39^,  97 Although ileostomy alone for acute complications has been abandoned, it has been used in the recent past with good success by Turnbull and co-workers, 111 in combination with skin-level transverse and sigmoid colostomies, for toxic megacolon. This is a relatively simple procedure that spares such desperately ill patients a major operative intervention until their acute illness has subsided. Because the procedure involves only decompression of the colon and does not remove the acutely inflamed tissue, most surgeons prefer colon resection.

 

SURGICAL MANAGEMENT

Total proctocolectomy with permanent Brooke ileostomy offers definitive treatment for ulcerative colitis by eliminating diseased mucosa and the risk of malignant transformation. Nevertheless, it remains controversial and is poorly accepted by patients and their physicians. Patients with a permanent ileostomy are incontinent of gas and stool and must wear a collecting bag day and night. As many as 40% to 50% of patients with Brooke ileostomies have appliance-related problems, and the psychologic and social implications, particularly for young patients, are tremendous. 78^,  89 Therefore, the search has continued for adequate alternatives to proctocolectomy and ileostomy.

Until recently, single-stage total proctocolectomy was the procedure of choice when complications of the disease were treated electively. This procedure is performed through a midline incision. The rectum is excised from the abdomen after mobilization and circumferential incision from the perineum. When cancer is not suspected, excision is performed rapidly, with division of the mesentery close to the bowel wall. This principle is especially important in the pelvic colon and rectum, where injury to the sacral parasympathetic nerves may lead to bladder and sexual dysfunction. Endorectal mucosal resection, as described later, appears to offer the best way to avoid such serious complications. 34 After standard proctocolectomy, management of the perineal wound is a problem, since chronic infection and poor healing may cause a lingering sinus tract between the buttocks. The authors’ preference is to apply active closed drainage to this area for 3 to 5 days following operation. Gauze packing of the perineum should be reserved for pelvic hemorrhage that cannot otherwise be controlled. Perineal wound problems may be reduced by performing an intersphincteric proctectomy, which entails dissecting between the internal and external anal sphincter when removing the rectum, thus preserving the levator ani and external anal sphincter muscles. These muscles can then be included in the closure of the perineum. Using this technique, complete healing of the perineum approaches 95% at 6 months.

 

 

The most important modification of the operation was the creation of an ileal pouch or reservoir proximal to the ileoanal anastomosis.

 

 

The most frequent late complication in patients undergoing ileoanal anastomosis is ileal pouch dysfunction or pouchitis, which has been reported to occur in 10% to 50% of patients undergoing this procedure for ulcerative colitis. Pouchitis is an incompletely defined and poorly understood clinical syndrome consisting of increased stool frequency, watery stools, cramping, urgency, nocturnal leakage of stool, arthralgias, malaise, and fever. The syndrome is similar to that found in patients with Kock continent ileostomy pouches. The etiology of this condition is unknown; speculations have included early Crohn’s disease, bacterial overgrowth or bacterial dysbiosis, either primary or secondary malabsorption, stasis, ischemia, and nutritional or immune deficiencies.

Mortality for elective surgical therapy is in the range of 0% to 2%; for emergency operation, it is about 4% to 5%; and for toxic megacolon, it rises to 17%. 5 These are remarkable statistics when one considers the debilitating nature of the disease and the fact that many patients have had long-term steroid therapy. The major complication in all reported series is sepsis, either in the wound or in the intra-abdominal cavity. There is little evidence that the development of more potent and specific antibiotics has significantly reduced the incidence of this complication; attention to the details of operative management continues to be the best way to ensure a smooth postoperative course. The most common late complication of resectional therapy with ileostomy or ileoanal anastomosis is intestinal obstruction, which occurs in about 10% of patients. Other bothersome but nonlethal complications following proctocolectomy include delay in perineal closure (25%), sexual dysfunction (5% to 10%), and renal stones (10%). Ileostomy dysfunction as a consequence of stenosis has been reduced to 2% by the Brooke-Turnbull ileostomy. Additional uncommon complications include prolapse, herniation, and ulceration of the stoma, which is usually a sign of the development of Crohn‘s disease within the ileal stoma. Whether the outcome following surgical therapy for Crohn’s disease of the colon is as favorable as for ulcerative colitis continues to be a source of controversy.

The formation of social groups (ileostomy clubs) has provided an important mechanism for the education of patients by those who have already mastered the technique of ileostomy management. Some hospitals have enterostomal therapists. These professionals are highly skilled in dealing with the physical and emotional problems of stomal management. In institutions that perform a large number of ileal pouch operations, specialized patient-oriented support groups are essential.

 

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