A sum score will be calculated based on the rating in each colonic segment. In order to assess validity and reliability in the rating scale both intra-observer and inter-observer reliability will be assessed. This will be done by taking representative high resolution digital photographs of all colonic segments during the withdraw phase of the colonoscopy. The photographs will be printed and de-identified. At the end of the study the PI will blindly grade each prep using photographs presented in a random fashion. A second experienced colonoscopist from the Temple faculty will also grade each prep to assess inter-observer reliability.