Original article Clinical endoscopy| Volume 83, ISSUE 5, P993-997, May 2016

Randomized, double-blind trial of CO2 versus air insufflation in children undergoing colonoscopy

Published:September 09, 2015DOI:

      Background and Aims

      Studies in adults have shown that postprocedural abdominal pain is reduced with the use of carbon dioxide (CO2) instead of air for insufflation during colonoscopy. The aim of our study was to compare postprocedural abdominal pain and girth in children undergoing colonoscopy using CO2 or air for insufflation.


      This was a prospective, randomized, double-blind study that included 76 consecutive pediatric patients undergoing colonoscopy for various indications. Patients were randomly assigned to either CO2 or air insufflation. At 2, 4, and 24 hours after the examination, the patients' pain was assessed by using the 11-point numerical rating scale. The waist circumference was measured 10 minutes and 2 and 4 hours after colonoscopy.


      A significantly higher proportion of patients had no pain after colonoscopy in the CO2 group compared with the air group (82 vs 37% at 2 hours and 95% vs. 63% at 4 hours, P < .001). Mean abdominal pain scores 2 and 4 hours after the procedure were statistically significantly lower in the CO2 group compared with the control air group (0.5 vs 2.6 at 2 hours and 0.1 vs 1.2 at 4 hours, P < .001). There was no difference in waist circumference between the 2 groups at all time intervals.


      The results of this randomized trial show clear benefits of CO2 insufflation for colonoscopy in reducing postprocedural discomfort. (Clinical trial registration number: NCT02407639.)


      CO2 (carbon dioxide), NRS-11 (11-point Numerical Rating Scale)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Gastrointestinal Endoscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Bretthauer M.
        • Thiis-Evensen E.
        • Huppertz-Hauss G.
        • et al.
        NORCCAP (Norwegian colorectal cancer prevention): a randomised trial to assess the safety and efficacy of carbon dioxide versus air insufflation in colonoscopy.
        Gut. 2002; 50: 604-607
        • Bretthauer M.
        • Lynge A.B.
        • Thiis-Evensen E.
        • et al.
        Carbon dioxide insufflation in colonoscopy: safe and effective in sedated patients.
        Endoscopy. 2005; 37: 706-709
        • Sumanac K.
        • Zealley I.
        • Fox B.M.
        • et al.
        Minimizing postcolonoscopy abdominal pain by using CO(2) insufflation: a prospective, randomized, double blind, controlled trial evaluating a new commercially available CO(2) delivery system.
        Gastrointest Endosc. 2002; 56: 190-194
        • Yoshida M.
        • Imai K.
        • Hotta K.
        • et al.
        Carbon dioxide insufflation during colorectal endoscopic submucosal dissection for patients with obstructive ventilatory disturbance.
        Int J Colorectal Dis. 2014; 29: 365-371
        • Saltzman H.A.
        • Sieker H.O.
        Intestinal response to changing gaseous environments: normobaric and hyperbaric observations.
        Ann N Y Acad Sci. 1968; 150: 31-39
        • Sajid
        • Caswell J.
        • Bhatti M.
        Carbon dioxide insufflation versus conventional air insufflation for colonoscopy: a systematic review and meta-analysis of published randomized controlled trials.
        Colorectal Dis. 2015; 17: 111-123
        • Yasumasa K.
        • Nakajima K.
        • Endo S.
        • et al.
        Carbon dioxide insufflation attenuates parietal blood flow obstruction in distended colon: potential advantages of carbon dioxide insufflated colonoscopy.
        Surg Endosc. 2006; 20: 587-594
        • Stevenson G.W.
        • Wilson J.A.
        • Wilkinson J.
        • et al.
        Pain following colonoscopy: elimination with carbon dioxide.
        Gastrointest Endosc. 1992; 38: 564-567
        • Roberts M.W.
        • Mathiesen K.A.
        • Ho H.S.
        • et al.
        Cardiopulmonary responses to intravenous infusion of soluble and relatively insoluble gases.
        Surg Endosc. 1997; 11: 341-346
        • Brecelj J.
        • Trop T.K.
        • Orel R.
        Ketamine with and without midazolam for gastrointestinal endoscopies in children.
        J Pediatr Gastroenterol Nutr. 2012; 54: 748-752
        • Ferreira-Valente M.A.
        • Pais-Ribeiro J.L.
        • Jensen M.P.
        Validity of four pain intensity rating scales.
        Pain. 2011; 152: 2399-2404
        • Church J.
        • Delaney C.
        Randomized, controlled trial of carbon dioxide insufflation during colonoscopy.
        Dis Colon Rectum. 2003; 46: 322-326
        • Uraoka T.
        • Kato J.
        • Kuriyama M.
        • et al.
        CO(2) insufflation for potentially difficult colonoscopies: efficacy when used by less experienced colonoscopists.
        World J Gastroenterol. 2009; 15: 5186-5192
        • Díez-Redondo P.
        • Gil-Simón P.
        • Alcaide-Suárez N.
        • et al.
        [Comparison between insufflation with air or carbon dioxide during the colonoscopy in sedated patients with propofol].
        Rev Esp Enferm Dig. 2012; 104: 411-417
        • Miró J.
        • Castarlenas E.
        • Huguet A.
        Evidence for the use of a numerical rating scale to assess the intensity of pediatric pain.
        Eur J Pain. 2009; 13: 1089-1095
        • Wouters M.M.
        • Van Wanrooy S.
        • Casteels C.
        • et al.
        Altered brain activation to colorectal distention in visceral hypersensitive maternal-separated rats.
        Neurogastroenterol Motil. 2012; 24: 678-685
        • Song X.
        • Chen B.N.
        • Zagorodnyuk V.P.
        • et al.
        Identification of medium/high-threshold extrinsic mechanosensitive afferent nerves to the gastrointestinal tract.
        Gastroenterology. 2009; 137: 274-284
        • Seo E.H.
        • Kim T.O.
        • Park M.J.
        • et al.
        The efficacy and safety of carbon dioxide insufflation during colonoscopy with consecutive esophagogastroduodenoscopy in moderately sedated outpatients: a randomized, double-blind, controlled trial.
        J Clin Gastroenterol. 2013; 47: 45-49