This paper is a retrospective, uni-institutional analysis that compares the polyp detection rate of water infusion versus conventional air insufflation colonoscopy. The queried database consisted of two groups based on the method of endoscopy used. There were 683 patients in the air group (1/2000-6/2006) and 495 in the water group (6/2006-6/2009). There were significantly more patients with at least one polyp in the water group compared to the air group. Similarly, there were more >9mm polyps. Overall adenoma detection rate was significantly higher in the water group. Water colonoscopy improves bowel preparation, which may contribute to higher polyp/adenoma detection.