It is our objective to improve the performance of CTC in the prepared colon, and to validate CTC in the unprepared colon for the detection of colorectal neoplasia. The cost-effectiveness ratio of CTC in the unprepared colon will compare favorably with other colorectal screening test.

To improve the diagnostic performance of CTC in the prepared colon using improved spatial resolution, advanced image displays, and computer-assisted diagnosis, and to optimize diagnostic performance of CTC in the unprepared colon for colorectal polyp detection using electronic stool subtraction and computer-aided diagnostic techniques. To estimate the sensitivity and specificity of CTC in the unprepared colon for clinically important colorectal neoplasms (large adenomas ≥ 1 cm) and to compare such estimates with colonoscopy. To survey patient acceptance of CTC in the unprepared colon, and to assess implications for health care costs and cost-effectiveness of CTC in the unprepared colon in comparison with other approaches.

Inclusion Criteria:

Average risk or higher for colorectal cancer and scheduled for colonoscopy with any of the following indications:

• Prior colorectal cancer, prior colorectal adenoma, strong family history of colorectal neoplasia, iron deficiency.
• Age ≥ 40 -100 years
• Known or highly suspected primary colorectal neoplasms > 10 mm (n = 160)
• Higher than average risk for colorectal cancer and scheduled for colonoscopy with any of the following indications: prior colorectal cancer, prior colorectal adenoma, strong family history of colorectal neoplasia, iron deficiency.

Exclusion Criteria:

• Less than 1/2 of colorectum remaining
• Inflammatory bowel disease (Crohns, Chronic Ulcerative Colitis)
• Familial Polyposis
• Melena, hematochezia

Mayo Clinic patients scheduled for colonoscopy.