Microperforation of a duodenal diaphragm as a cause of paradoxical gas in congenital duodenal obstruction.

An infant who presented with signs of duodenal atresia had proximal duodenal obstruction by upper gastrointestinal barium study, but had a small amount of air in the distal bowel. Exploration showed an annular pancreas and microperforation of a duodenal diaphragm. Prior to concluding that pancreaticobiliary duct anomalies are the path of air into the distal bowel in patients with duodenal atresia, microperforation of a duodenal diaphragm must be excluded.