Pain following colonoscopy: elimination with carbon dioxide

Gastrointest Endosc. 1992 Sep-Oct;38(5):564-7. doi: 10.1016/s0016-5107(92)70517-3.


Fifty-six patients have been examined in a prospective randomized study on the effects of air and carbon dioxide on post-procedural discomfort following colonoscopy. A significant reduction in post-procedural pain was observed at 6 hours (p = < 0.0005) and was still present the next day (p = 0.01). This was associated with a difference in the grading of flatus at 6 and 24 hours (p = < 0.0001 and < 0.05, respectively). An abdominal radiograph 1 hour after the procedure showed minimal gas in the CO2 patients, while the patients who had air showed distention of large and small bowel (p = < 0.0001 and < 0.01, respectively). Seventeen of 29 patients who had air suffered post-procedural pain, compared with 2 of 27 of the CO2 patients. Fifty-seven percent of the patients who were given air had colonic diameters over 6 cm on a 1-hour post-colonoscopy radiograph and 18% over 10-cm diameter. Provision by equipment manufacturers of simple and safe devices for routine delivery of CO2 for lower gastrointestinal endoscopy is long overdue.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Carbon Dioxide*
  • Colon / diagnostic imaging
  • Colonoscopy / adverse effects*
  • Colonoscopy / methods
  • Flatulence
  • Humans
  • Insufflation
  • Intestine, Small / diagnostic imaging
  • Pain / prevention & control*
  • Prospective Studies
  • Radiography


  • Carbon Dioxide