Colorectal cancer is a leading cause of cancer death in the United States. Mortality remains high because most colorectal cancers are detected after there has been regional or distant spread, precluding curative surgical resection. With this in mind, screening strategies have been recommended for asymptomatic individuals which hope to reduce mortality from colon cancer by detecting and removing premalignant adenomatous polyps or early malignant lesions. Screening of asymptomatic individuals over age 50 with sigmoidoscopy and fecal occult blood tests has been advocated by the American Cancer Society. However, current screening will identify only 50% of patients who have adenomatous polyps. More sensitive tests for polyp detection, like colonoscopy, are costly, require extensive resources and are unlikely to be used for screening large populations. Ideal screening would identify patients with the highest risk of cancer and target more sensitive screening tests at this population. The identification of low cost, easily collectible risk factors which can be used to target patients for the more sensitive screening tests is the primary purpose of this study. Since a major segment of the veteran population is over the age of 50, there will be a substantial impact in reduction of both mortality and morbidity due to colon cancer and attendant cost savings to the VA for treatment if such risk factors can be identified.