Objective Water immersion insertion and carbon dioxide (CO 2 ) insufflation, as alternative colonoscopic techniques, are able to reduce patient discomfort during and after the procedure. We assessed whether the combination of water immersion and CO 2 insufflation is superior in efficacy and patient comfort to other colonoscopic techniques.Methods In a prospective, randomized study, a total of 420 patients were randomized to either water immersion insertion and CO 2 insufflation during withdrawal (water/ CO 2 ), water insertion and air insufflation during withdrawal (water/air), CO 2 insufflation during both insertion and withdrawal (CO 2 /CO 2 ), or air insufflation during both insertion and withdrawal (air/air). The main outcome was the success of minimal sedation colonoscopy, which was defined as reaching the cecum without switching to another insertion method and without additional sedation beyond the initial 2 mg of midazolam. Patient comfort during and after the procedure was assessed.Results A total of 404 patients were analyzed. The success rate of minimal sedation colonoscopy in the water insertion arm (water/CO 2 and water/air) was 97% compared with 83.3% in the gas insertion arm (CO 2 /CO 2 and air/air; P < 0.0001). Intraprocedural pain and bloating were significantly lower in the water/CO 2 group than in all other groups. Patient discomfort in the water/CO 2 group during 24 h after the procedure was comparable with that in the CO 2 /CO 2 group and significantly lower than that in the air groups (water/air and air/air). No complications were recorded during the study.
ConclusionThe combination of water immersion and CO 2 insufflation appears to be an effective and safe method for minimal sedation colonoscopy. Overall patient discomfort was significantly reduced compared with that in other techniques. Eur J Gastroenterol Hepatol 24:971-977 c