Several prospective studies in adults have confirmed the efficacy and safety of CO2 insufflation in comparison with atmospheric air insufflation during colonoscopy. CO2 insufflation was associated with decreased post-procedural abdominal pain, which likely stems from the fact that, in comparison to air, absorption of CO2 from the colon is much faster due to a much greater water solubility. Animal studies have also shown that CO2 insufflation results in less disturbance of parietal blood flow due to its potential vasodilating effect. Insufflation of colon with CO2 did not prolong the procedure or lengthen the time to reach the terminal ileum and was proven to be safe in both sedated and non-sedated patients . The use of CO2 for colon insufflation could possibly lead to CO2 retention and increased levels in the blood thus interfering with acid-base balance . However, previous studies reported that carbon dioxide insufflation did not cause increased CO2 levels in the blood or end-tidal CO2 (ETCO2) and complication rates were not increased when using CO2. Because of its advantages CO2 insufflation has become a standard of care in adult colonoscopy.