7026 Double blind randomised controlled trial comparing carbon dioxide and air insufflation during colonoscopy; assessing patient bloating, discomfort and satisfaction.

Aim:To determine if the routine use of carbon dioxide, as opposed to air, insufflation during colonoscopy significantly reduces patient discomfort and bloating, thus increasing satisfaction. Method: 104 consecutive volunteers, aged 55 to 65, attending for a screening colonoscopy or for adenoma assessment as part of the MRC Flexiscope trial, were randomly allocated to receive either carbon dioxide or air insufflation. Carbon dioxide was delivered to the video-endoscopes using the Olympus Endoscopic CO2regulator. The volunteers completed a questionnaire the morning after the colonoscopy and posted it to an independent address. Procedural and post-procedural discomfort and bloating were measured using 100mm visual analogue scales. Global measures of physical discomfort, anxiety and satisfaction were obtained using a previously validated satisfaction questionnaire. Results: 104 volunteers agreed to participate in the trial, questionnaires were received from 89 participants (86% return rate). Analyses were performed on an intention to treat basis. No significant difference was found for global discomfort, anxiety or satisfaction measured using the satisfaction questionnaire (Mann-Whitney U test). Conclusion: The routine use of carbon dioxide insufflation in colonoscopy significantly reduces bloating both during and after the procedure and post-procedural discomfort, but not procedural discomfort. There was no impact on global assessment of discomfort, anxiety or satisfaction. This research was made possible through an MRC grant t...