Lower gastrointestinal bleeding is a common reason for hospitalization, especially among the elderly. Unlike that of upper gastrointestinal bleeding, the diagnostic and therapeutic approach to individuals with lower gastrointestinal bleeding is not well standardized. Recent reports indicate that early colonoscopy may be the best strategy to improve outcomes and reduce costs. However, good prospective, controlled data on the role of colonoscopy in the management of lower gastrointestinal bleeding are still required. Colonoscopy can establish a definite or probable diagnosis in greater than 80% of individuals with lower gastrointestinal bleeding. Based on the best available evidence, it appears that clinical and colonoscopic data may be combined in an effort to predict outcome and suggest optimal length of stay. It also appears that therapeutic colonoscopy can arrest or prevent bleeding in certain high-risk patients, offering the opportunity to change the natural history of the bleed.