Abstract: Colorectal carcinoma is the most common malignancy of the gastrointestinal tract and the second leading cause of cancer deaths. Five-year survival rate in patients with localized disease is 94%. Early detection and subsequent prompt treatment of colorectal carcinomas provide a better five years survival rate. Higher detection rate can be achieved if patients over 40 years of age with symptoms are submitted to a series of investigations including sigmoidoscopy, barium enema and colonoscopy. Colon cancer screening not only detects the disease at an early, more favorable stage, but also prevents disease by removing premalignant polyps.