Comparison of Adenoma Detection Rate Among Water, Carbon Dioxide and Air Methods of Minimal Sedation Colonoscopy

Overview

The purpose of this study is to determine which of the methods of colonoscopy viz. water insufflation or air insufflation or carbon dioxide insufflation is better in detecting the adenomas in colon and also which of these methods is best tolerated by patients. Hypothesis: the investigators hypothesize that in patients undergoing first time screening colonoscopy a higher Adenoma Detection Rate will be found in the proximal colon in the group randomized to the water method compared to those randomized to the air or CO2 insufflation methods

Significance: ADR is an independent predictor of risk of post screening colonoscopy colon cancer. A simple method solely controlled by the colonoscopist that enhances proximal ADR holds the promise of rectifying some of the unresolved shortcomings of screening colonoscopy in failing to reduce the occurrence of post screening incident cancers in the proximal colon and the associated cancer mortality. Hypotheses \& Specific Aims: Primary Hypothesis: In patients undergoing first time screening a higher ADR will be found in the proximal colon in those randomized to the water method compared to those randomized to the air method or CO2 method. Secondary Hypotheses: The examination method but not co-variables, procedure-related or patient-centered outcomes, is an independent predictor of proximal colon ADR. Specific Aims: This is a prospective, randomized, single-blinded controlled study to compare the study (water) and control 1 (air) method and control 2 (CO2 method) to aid insertion of the colonoscope. The proximal colon ADR, total ADR, co-variables, procedure-related and patient-centered outcomes and adverse event during and within 30 days of colonoscopy will be recorded and compared between the study and control methods.