Is carbon dioxide as an insufflation agent for double contrast barium enema still worthwhile after a same-day flexible sigmoidoseopy?

PURPOSE: The aim of the study was to evaluate the efficacy of a double-contrast barium enema (DCBE) with CO2 as a distending gas after a screening flexible sigmoidoscopy for reducing abdominal distension after an examination. PATIENTS AND METHODS: A total of 165 DCBEs for patients with positive faecal occult blood tests were randomly allocated to a CO2 group (n = 83) and a control group (n = 82) using air. Abdominal radiograph were taken before the DCBE, immediately following it, and 30 minutes later to determine residual bowel gas. The degree of abdominal discomfort was recorded using a scoring system. RESULTS: The patients in the CO2 group had significantly smaller amounts of residual gas 30 minutes after the DCBE than did the control group, both in the colon (P < 0.02) and in the small intestine (P < 0.001). There was significantly less abdominal distension after the DCBE in the CO2 group compared to the control group (P < 0.001). The abdominal discomfort score at 30 minutes after CO2 correlated with the residual gas in the small intestine (r = 0.390, P = 0.003) but not in the colon (r = 0.155, P = 0.15). The quality of the images and the number of polyps detected did not differ between two groups. CONCLUSIONS: We concluded that using CO2 when administering a DCBE after a screening sigmoidoscopy was useful for relieving abdominal discomfort following the examination; furthermore, it did not impair the diagnostic ability of the DCBE. (C) 2002 The Royal College of Radiologists.