Gas insufflation is mandatory to ensure good visualisation during colonoscopy. Currently, air is commonly
used for this purpose (Janssens et al. 2009). However, significant amounts of air can be retained
in the GI tract (Bretthauer et al. 2003) causing pain and discomfort for the patient. Pain associated
with colonoscopy has been identified as a major barrier to participation in CRC screening
Randomised trials have shown that carbon dioxide insufflation significantly reduces abdominal pain
and discomfort in patients undergoing colonoscopy and flexible sigmoidoscopy (Bretthauer et al.
2002a; Bretthauer et al. 2002b; Sumanac et al. 2002; Church & Delaney 2003; Wong et al. 2008)
Side effects of C02 insufflation were not detected in unsedated patients in two randomised studies
identified in the present literature search and involving 350 patients (Bretthauer et al. 2002b; Bretthauer
et al. 2005). Slightly elevated end-tidal C02 levels were detected in sedated patients in the latter
study, but only 52 sedated patients were included in the study and patients with chronic obstructive
pulmonary disease, as well as patients with known C02 retention, were excluded.
Since carbon dioxide is an inert gas that cannot form a combustible mixture with hydrogen and methane,
C02 insufflation will avoid the very rare risk of explosion during sigmoidoscopy or colonoscopy
Following incomplete colonoscopy, an alternative examination is frequently required. Provided adequate
facilities are available, same-day CT or MRI colonography, or, in appropriate cases, doublecontrast
barium enema would be desirable. However, same-day radiologic examination following
colonoscopy frequently yields suboptimal quality when air insufflation is used for colonoscopy, due to
retained air in the colon. If CO2 insufflation has been used, same-day radiologic imaging is generally
feasible with appropriate quality. This avoids the necessity of scheduling the additional radiologic examinations
on another day and further colon cleansing (Phaosawasdi et al. 1986; Rodney, Randolph &
Peterson 1988)
In light of the above evidence and considerations:
Carbon dioxide insufflation is recommended for colonic endoscopic procedures (I - A).Rec 5.31
Carbon dioxide insufflation should be avoided in patients with COPD, known C02 retention or otherwise
reduced pulmonary function (VI - A).
