Does the Cap Increase the Finding of Polyps When Water Exchange Colonoscopy is Used

This is a study to compare two different, but normally, used methods of colonoscopy in patients that require a routine or repeat colonoscopy. There will be three arms in this study: WE water control, water plus Cap-1, and water plus Cap-2. The patient will prepare himself/herself for the colonoscopy as per normal instructions and he/she will be given the information for the study at that time so that he/she can make a decision to participate in the study. The control method will use water instead of air inserted into the colon. The study method will use a new accessory, a cap that will fit onto the end of the colonoscope plus water during the procedure. This study will also confirm if using the cap method with water is a better way of detecting polyps in the colon and possibly cancer.