A Comparison of Air Insufflation, Water Immersion and Water Exchange Colonoscopy in CRC Screening

Water-aided method for colonoscopy can be broadly subdivided into two major categories. Water Immersion (WI), characterized by suction removal of the infused water predominantly during the withdrawal phase of colonoscopy, and Water Exchange (WE), characterized by suction removal of infused water predominantly during the insertion phase of colonoscopy. Several studies showed that WE significantly reduces pain compared to WI and colonoscopy with traditional air insufflation (AI), increases the number of unsedated procedures and adenoma detection rate (ADR), in particular proximal ADR. This randomized controlled trial will be a direct comparison of Air Insufflation, Water Immersion and Water Exchange to test the hypothesis that WAC (particularly WE) would significantly decrease pain score during colonoscopy in average-risk screening patients. Several other secondary outcomes will also be analyzed.