Air enema used in the evaluation of acute colitis. A comparison between instant radiography and endoscopy.

Objective: The purpose of this study was to evaluate air enema as a method of assessing acute colitis.

Methods: Twenty-seven patients with symptoms of acute colitis underwent plain abdominal radiography, air enema, and colonoscopy within 48 h. The films were evaluated by 3 observers with different levels of experience, both independently and together, and the results were then compared to the findings at endoscopy.

Results: Air enema visualized a greater part of the colon than plain abdominal radiography. When air enema was compared to endoscopy as the reference, it showed good correlation, with a positive predictive value of 92% (sensitivity 62%, specificity 85%). Evaluation of the rectum was less accurate, a finding that emphasized the importance of rigid sigmoidoscopy.

Conclusions: Air enema is a useful diagnostic method in acute colitis, it is easily performed and tolerated well with no observed complications. It is also easy to interpret, as shown by a high level of agreement (kappa = 0.67) among the 3 independent observers with very different levels of experience.