Air versus carbon dioxide insufflation in double contrast barium enemas: the role of active gaseous drainage.

Air has been traditionally used as the negative contrast agent in double contrast barium enema (DCBE) examinations, but causes abdominal pain in the 24 h following the procedure. The frequency of post-procedural pain is less when carbon dioxide (CO2) is used as the negative contrast agent. We evaluated patients following DCBE examinations (using either air or CO2) by means of a questionnaire, to determine whether active drainage of gas altered the post-procedural pain. There was no difference in the pain experienced in the groups receiving CO2 with either active or passive drainage, or in the group receiving air with active drainage. Compared with the other groups there was a significantly higher incidence and severity of pain in the group receiving air and passive drainage. We conclude that active drainage of air following a DCBE examination is as effective as using CO2 in reducing post-procedural pain and swelling.