The goal of this study is to compare, both clinically and from a cost-effectiveness perspective, virtual or CT-C (CT-Colonography) to standard CT scan and optical colonoscopy (OC). Virtual colonoscopy is a combination of a radiologic evaluation of the abdomen and pelvis with intra-colonic imaging. Previous research supports the concept that CT-C may be an effective substitute for the current OC and address limited compliance for surveillance for CRC survivors. Post-operative CRC surveillance strategies are effective, but depend upon patient compliance which is less than desired. Improved adherence is linked with greater cost-effectiveness as well as better clinical outcomes. CT-C possesses potential advantages: convenience as a single test, less risk, possibly patient preference and lower total costs. Costs would be reduced through direct (provision of fewer optical colonoscopies) and indirect means (reduction in time lost from work by patient and chaperone, etc.). When extrapolated across the roughly 200,000 OCs performed annually in the US for this indication reduced utilization of even 50% in a high unit cost procedure like OC would yield substantial savings without a reduction in clinical quality.