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Inflammatory Bowel Disease

Initial Evaluation of Chronic Diarrhea

The initial diagnostic evaluation of chronic diarrhea includes stool cultures for enteric pathogens, tests for ova and parasites, Clostridium difficile toxin, and fecal leukocytes. Specific cultures for Yersinia enterocolitica, isolation of toxigenic strains of Escherichia coli, and serologic titers for Entamoeba histolytica

In patients who are immunocompromised or who engage in high-risk sexual behavior, evaluation may include Chlamydia trachomatis, Cryptosporidium species, Neisseria gonorrhoeae, herpes simplex virus, Isospora belli, cytomegalovirus.

Laboratory studies to assess disease activity and nutritional state include levels of C-reactive protein, which correlates with severity of disease, and levels of serum proteins (eg, albumin, transferrin, prealbumin, retinol-binding protein), which assess nutritional status. The degree of anemia indicates the severity of Severe colitis may cause hypoproteinemia and hypoalbuminemia.

Colonoscopy or flexible sigmoidoscopy with biopsy is valuable in characterizing mucosal injury, its pattern and the extent of involvement.

Abdominal plain films with the patient in upright and supine positions should be obtained in patients with severe disease to detect perforation, toxic megacolon, or thumbprinting, any of which constitutes a medical and surgical emergency.

Ulcerative Colitis

Ulcerative colitis (UC) is the most common cause of chronic colitis. The pathogenesis remain unknown. Inflammation is localized primarily in the mucosa; it involves the rectum and may involve part or all of the large bowel.

The incidence ranges from 4 to 15 cases per 100,000. Disease may present at any time but does so most often during adolescence and young adulthood, with a higher risk of the disease in young females than males. Among family members, the risk is tenfold higher. Ashkenazi Jews are afflicted more often than non-Jewish populations.

Thirty percent of UC patients present with disease limited to the rectum, 40% with more extensive disease but not extending beyond the hepatic flexure, and 30% with total colonic involvement.

The most common symptoms are abdominal pain, rectal bleeding, diarrhea, fever, and malaise.

Diagnostic Evaluation

Inflammation characteristically begins in the rectum. The mucosa is erythematous, friable, and edematous, with superficial erosions and ulcerations.

Histologic features of ulcerative colitis include diffuse shallow ulceration of the mucosa, crypt abscesses, thickening of the muscularis mucosa, and pronounced inflammatory cell infiltration.

Extraintestinal Manifestations

Musculoskeletal. Peripheral (colitic) arthritis is the most common extraintestinal manifestation of ulcerative colitis. It is migratory, often involving the hip, ankle, wrist, or elbow. It is usually monoarticular and asymmetric, and its course parallels that of the colitis. Ankylosing spondylitis and sacroiliitis, or axial arthritis, typically present as low back pain with morning stiffness.

Ocular. Episcleritis, uveitis, and iritis may occur.

Dermatologic. Abnormalities may include erythema nodosum, pyoderma gangrenosum, lichen planus, and aphthous ulcers of the mouth.

Hepatobiliary. Manifestations may include hepatic steatosis, primary sclerosing cholangitis (4%), cholelithiasis, and pericholangitis.

Miscellaneous. Other complications include nephrolithiasis and a hypercoagulable state.

Crohn Disease

Crohn disease (CD) is an inflammatory bowel disease.