The researchers will use specific variations in stool tagging techniques to determine the best image quality of CT data (e.g., homogenous tagging of fluid and stool), and highest patient acceptability, as well as evaluate the adequacy of preparation for same-day colonoscopy. Diagnostic reader performance will focus on the accuracy for detecting all neoplastic lesions including colon cancers, adenomatous polyps, sessile adenomas and flat adenomas. Most importantly, these results will help inform the design of a larger trial of an optimized CT colonography technique in a community setting.