Colonoscopy: Randomized Comparative Study of Insufflation with Carbon Dioxide versus Air

BACKGROUND In Brazil, an increasing number of people are submitted to colonoscopy, either for screening or for therapeutic purposes. AIM To evaluate whether there are advantages of using carbon dioxide (CO2) over air for insufflation. METHODS Two hundred and ten of 219 patients were considered eligible for this study and were randomized into two groups according to the gas insufflation used: Air Group (n=104) and CO2 Group (n=97). The study employed a double-blind design. RESULTS The Air and CO2 Groups were similar in respect to bowel preparation evaluated using the Boston scale, age, gender, previous surgery, maneuvers necessary for the advancement of the device, and presence of polyps, tumors or signs of diverticulitis. However, "waking up with pain" and "pain at discharge" were more prevalent in the Air Group, albeit not statistically significant, with post-exam bloating seen only in the Air Group. The responses to a questionnaire, applied to analyze the late post-exam period, showed more comfort with the use of CO2. CONCLUSIONS The use of CO2 is better than air as it avoids post-examination bloating, thereby providing greater comfort to patients.