Early cancer detection. Colorectal cancer.

Persons with symptoms or signs suggestive of colorectal cancer require complete exam of the large bowel either by sigmoidoscopy, preferably flexible, with barium enema, or by total colonoscopy. A test for fecal occult blood (FOBT) is not necessary here. In asymptomatic persons at average risk for colorectal cancer, the following screening recommendations are made: from age 40, annual digital rectal exam and FOBT; and, from age 50, sigmoidoscopy, preferably flexible, every 3 to 5 years after two negative annual exams. If there is a family history of colorectal cancer in one or more first-degree relatives, annual digital rectal exam and FOBT should begin at age 40, with either barium enema and sigmoidoscopy or total colonoscopy every 3 to 5 years. Persons with a history of chronic ulcerative colitis, polyposis syndromes, or prior colorectal adenomas or cancer merit special attention.