– A chronic inflammatory mucosal disease of the colon and rectum characterized by bloody diarrhea.
Causes and Incidence
The cause of ulcerative colitis is unknown. Immunologic factors, infectious agents, toxins, and dietary factors have been studied extensively but with no promising result. The annual incidence of ulcerative colitis in the United States is 7 cases per 100,000 people. The incidence distribution is bimodal, with peak frequencies between 15 and 25 years of age and between 50 and 70 years of age. It is most prominent in whites, especially American and European Jews.
The disease process usually begins in the rectosigmoid area and spreads proximally. Pathologic change starts with degeneration of the reticulin fibers beneath the epithelial mucosa. This causes occlusion of the subepithelial capillaries and infiltration of the lamina propria with lymphocytes, leukocytes, eosinophils, mast cells, and plasma. The result eventually is abscess formation, necrosis, and ulceration of the epithelial mucosa. This in turn reduces the colon’s ability to absorb sodium and water.
The primary sign is the presence of frequent spells of bloody, mucoid diarrhea accompanied by abdominal cramping. As the ulceration extends proximally, the stools become looser and increase in frequency, to as many as 20 daily. Malaise, fever, anorexia, and weight loss may also be present by this time.
Complications include perforation, toxic megacolon, massive hemorrhage, and an increased risk of adenocarcinoma of the colon.
A tentative diagnosis can be made on the history and examination of a stool specimen. Confirmation is made by sigmoidoscopy, which reveals a granular, friable mucous membrane with crypt abscesses, loss of normal vascular pattern, and scattered areas of hemorrhage. Plain x-rays of the abdomen may assist in gauging the extent and severity of disease. Stool cultures must be obtained to rule out all possible infectious bowel disorders. They should be negative in ulcerative colitis.
Colectomy or proctocolectomy with permanent ileostomy for fulminant disease, hemorrhage, perforation, or toxic megacolon.
Corticosteroids in retention enema or systemic form, depending on severity of disease; antidiarrheal drugs to control diarrhea; folate supplements; sulfasalazine drugs to help reduce inflammation and maintain remission; analgesics for pain (avoid aspirin and nonsteroidal antiinflammatory drugs because they may be irritating; avoid opiates and anticholinergics if disease is severe and the individual is at risk of toxic megacolon); immunosuppressives are being used in clinical trials to treat severe disease.
Avoidance of irritating foods (e.g., high-fiber foods, raw fruits and vegetables); adequate fluids; acute attacks treated with bed rest, IV fluids, total parenteral nutrition for severe malnutrition, and blood replacement; referral to support groups for long-term coping with disease; dietary education; ostomy care and instructions if needed; counseling to aid adaptation to altered body image with ostomy.