I-scan for Adenoma Detection

This is a randomized controlled trial comparing the use of i-scan (digital surface and contrast enhancement of the mucosa) versus standard high-definition white light for the detection of conventional adenomas and sessile serrated adenomas/polyps. Recent studies have indicated that colonoscopy is more effective in preventing cancer in the left side of the colon than the right side of the colon. The reasons for this difference may be partly biologic, in that a special group of polyps known as sessile serrated adenomas/polyps (SSA) are located primarily proximal to the splenic flexure. Sessile serrated adenomas/polyps share molecular features with a group of cancers that occur primarily in the proximal colon. These molecular features include CpG island methylator phenotype (CIMP) and microsatellite instability. These lesions are endoscopically subtle in that they are often flat, have the same color as the surrounding mucosa, and are hard to differentiate from normal mucosa. Recent studies have shown that image enhanced endoscopy can highlight the appearance of these lesions. This study will test whether i-scan increases the detection of conventional adenomas and sessile serrated adenomas/polyps in a randomized controlled trial.