 One such emerging technique which shows promise for improving adenoma detection rate is water colonoscopy. In one of the early studies employing the water method a trend towards a higher ADR in the water method group was recognized 37 vs. 26. The observation prompted a retrospective analysis of 1178 cases of screening and surveillance colonoscopy performed by a single endoscopist at the Sacramento VAMC, which showed an overall ADR presence of at least one adenoma of 27 with air colonoscopy whereas that for the water method colonoscopy was 35 p0.007. In a subsequent combined analysis of two prospective RCT of air vs. water colonoscopy for screening and surveillance using scheduled unsedated colonoscopy 5 and on-demand sedation 6, more patients were found to have at least one diminutive adenoma in the proximal colon in the water method group than in the air group 28 vs. 14, respectively, p0.0298. Another quasi randomized study of screening patients performed at Phoenix VAMC using high definition equipment confirmed a significantly higher overall ADR with the water method n177 compared with the air method n191 57 vs. 46 p0.03. The odds of detecting an adenoma was 81 higher with the water method OR 1.81; 95 CI: 1.12-2.90 and independent of age, body mass index BMI, current smoking and alcohol use, withdrawal time quality of bowel preparation. In the proximal colon ADR was significantly higher in patients examined with the water method than with air method 46 vs. 35 p0.03, particularly for adenomas 10 mm in size 38 vs. 25 p007. These encouraging preliminary data reflect the potential benefits of water method colonoscopy. 