The peroral pneumocolon revisited: a valuable fluoroscopic and CT technique for ileocecal evaluation

The peroral pneumocolon represents a time-honored but somewhat forgotten and underutilized technique for improved ileocecal evaluation at small bowel fluoroscopy. The peroral pneumocolon entails fluoroscopically guided gaseous insufflation per rectum following the arrival of barium at the cecum at conventional small bowel follow-through examination. In most cases, high-quality double contrast evaluation of the terminal ileum can be achieved, often superior to enteroclysis examination for this critical location. The peroral pneumocolon improves diagnostic confidence, including assessment of disease activity, and may result in a reversal of the diagnostic impression. This simple procedure will be discussed and a spectrum of fluoroscopic findings with CT and endoscopic correlation will be provided to demonstrate the added yield of this technique in the evaluation of known or suspected Crohn's disease. Application of the pneumocolon technique to CT for combined small and large bowel evaluation ("CT coloenterography") will also be discussed, which represents an attractive new option for investigating inflammatory bowel disease and other bowel-related conditions. Through the use of automated low-pressure carbon dioxide delivery per rectum, supplemented by IV glucagon for relaxation of the ileocecal valve, a CT-based pneumocolon examination may prove to be a useful hybrid technique for bowel evaluation in the future.