Polyps of the Colon and Rectum

POLYPS OF THE COLON AND RECTUM

A polyp is a mass of tissue that protrudes into the lumen of the bowel. Polyps can occur anywhere in the intestinal tract and rectum. They can be classified as neoplastic (ie, adenomas and carcinomas) or non-neoplastic (ie, mucosal and hyperplastic). Non-neoplastic polyps, which are benign epithelial growths, are common in the Western world. They occur more commonly in the large intestine than in the small intestine. Although most polyps do not develop into invasive neoplasms, they must be identified and followed closely. Adenomatous polyps are more common in men. The proportion of these polyps arising in the proximal part of the colon increases with age (after 40 years of age). Prevalence rates vary from 25% to 60%, depending on age. Non-neoplastic polyps occur in 80% of the population, and their frequency increases with age (Wolfe, 2000).

Clinical manifestations depend on the size of the polyp and the amount of pressure it exerts on intestinal tissue. The most common symptom is rectal bleeding. Lower abdominal pain may also occur. If the polyp is large enough, symptoms of obstruction occur. The diagnosis is based on history and digital rectal exam-ination, barium enema studies, sigmoidoscopy, or colonoscopy.

After a polyp is identified, it should be removed. There are sev-eral methods: colonoscopy with the use of special equipment (ie, biopsy forceps and snares), laparoscopy, or colonoscopic excision with laparoscopic visualization. The latter technique enables im-mediate detection of potential problems and allows laparoscopic resection and repair of the major complications of perforation and bleeding that may occur with polypectomy. Microscopic examina-tion of the polyp then identifies the type of polyp and indicates what further surgery is required.