Endoscopic screening for colorectal cancer.

There is strong evidence that colon screening of asymptomatic, average-risk subjects can reduce colorectal cancer mortality. Endoscopic screening with sigmoidoscopy can reduce mortality associated with left-sided cancers due to the discovery of early curable cancers and the detection removal of premalignant adenomas. Screening with colonoscopy is widely accepted for high-risk groups and would likely be effective for the screening of average-risk subjects.