Carbon dioxide or air in double-contrast enemas: a study of the pain and discomfort during and after examination

Abstract

This prospective randomized double-blind study was done to assess the difference between carbon dioxide (CO₂) and air regarding pain and discomfort during and after double-contrast enemas, and to find a possible explanation of why prior investigations have come to different conclusions regarding the usefulness of CO₂. Using a questionnaire opinions regarding pain and discomfort during and 30 mins, 2 h and 8 h after a double-contrast enema with either CO₂ or air were collected from 142 and 120 patients, respectively. The study has shown less pain and discomfort 30 min and 2 h after the enema when CO₂ was used, whereas there is no significant difference during the examinations and after 8 h. Together with the fact that there are patients reporting worsening pain after the exam, this might explain the differences between earlier investigations. Because CO₂ gives less pain than air it is recommended as a negative contrast medium in double-contrast enemas, although the distension of the bowel is not as good as with air.