Population-based prevalence estimates of history of colonoscopy or sigmoidoscopy: review and analysis of recent trends.

Lower GI endoscopy, such as colonoscopy or sigmoidoscopy, is thought to have a substantial impact on colorectal cancer incidence and mortality through detection and removal of precancerous lesions and early cancers. We aimed to review prevalence estimates of history of colonoscopy or sigmoidoscopy in the general population and to analyze recent trends.