Review: hemoccult screening reduces death from colorectal cancer in average-risk patients > 50 years of age.

S t u d y s e l e c t i o n English-language studies were selected if they evaluated Hemoccult testing, flexible sigmoidoscopy, or genetic testing as the first step in a multiphase secondary prevention strategy or colonoscopy as a single-phase secondary prevention strategy in both asymptomatic and high-risk patients. Studies that screened with digital rectal examination and doublecontrast barium enema were excluded.