Recent studies indicate that infusing 300 milliliters of water (in lieu of air) into the rectum and left colon through the colonoscope as it is being inserted during a colonoscopy examination can allow easier endoscope advancement. This method may prevent stretching of the colon, and ultimately reduce pain induced during colonoscopy. Improvements in patient comfort and cooperation, may increase the efficiency and success rate of complete colonoscopy. The purpose of the study is to test the efficacy of the water immersion technique in patients colonoscopy.