Screening for colorectal cancer.

Screening for a disease is an important concept in modern day preventive medicine. The aim is early disease detection and treatment of both asymptomatic individuals and those at risk of the disease, with the goal of better survival. The WHO published a set of essential criteria for screening in 1968 and colorectal cancer has been identified as a candidate disease. Three methods of screening are evaluated here: fecal occult blood test, flexible sigmoidoscopy and colonoscopy. Newer techniques are still being studied and preliminary results are encouraging. The incidence of colorectal cancer in Asia has been increasing in association with changes in lifestyle and therefore, designing efficient, acceptable screening programs for these populations is an important issue in the prevention of this common malignant disease.