Efficacy of carbon dioxide-insufflating colonoscopy in patients with irritable bowel syndrome: A randomized double-blind study

Background and Aim:  Colonoscopy has the disadvantage of pain and discomfort for patients. It has been shown in randomized controlled trials that carbon dioxide (CO2) insufflations significantly reduce pain and discomfort in patients undergoing colonoscopy. However, there have been no studies in which CO2 insufflation in colonoscopy of patients with irritable bowel syndrome (IBS) was investigated. Methods:  Randomized double-blind controlled study was conducted to assess the suffering from colonoscopy in patients with IBS and the efficacy of CO2 insufflation in colonoscopy for patients with IBS. Patients with IBS and controls who received colonoscopy were randomized into an air or CO2 insufflation group. Patients' symptoms such as distension and pain were compared using a 10-cm visual analog scale (VAS). Results:  There were 18 patients in the IBS/air group, 19 patients in the IBS/CO2 group, 25 patients in the control/air group and 26 patients in the control/CO2 group. The mean value of severity of distension after colonoscopy and the mean value of severity of pain from during examination to one hour after the examination were higher in the IBS group than in the control group. The severity of these symptoms was reduced earlier in the CO2 group. CO2 insufflation in colonoscopy was more effective in the IBS group than in the control group from 15 min to one hour after the examination. Conclusion:  Regarding colonoscopy-related suffering, IBS patients showed significant differences from non-IBS patients. CO2 insufflation in colonoscopy is effective for IBS patients, particularly for patients who commence activities after colonscopy.