A twelve-day-old male presented with non-bilious, non-bloody emesis 2 hours after feeding since two-days-old, with flatus and light stools since birth. An upper gastrointestinal series (UGI) at an outside institution was reported as normal. Abdominal radiographs demonstrated distal bowel gas with proximal duodenal dilation. Abdominal ultrasound demonstrated gas in the main pancreatic duct and a dilated, fluid-filled duodenum. An UGI revealed duodenal atresia with enteric bypass by congenital anomaly of the pancreaticobiliary system. At thirteen days old the patient underwent uncomplicated duodenoduodenostomy. The post-operative course was uneventful and the patient subsequently tolerated oral feeds.

Bypass of the atretic duodenal segment through an anomalous pancreatic ductal system is a rare anomaly described in the literature in only a handful of cases. This case report highlights the importance of considering duodenal atresia and pancreaticobiliary enteric bypass in the differential diagnosis of neonates presenting with partial duodenal obstruction. On ultrasound, the presence of gas in the biliary tree or pancreatic duct should alert the physician to the possibility of duodenal atresia with congenital pancreaticobiliary duct anomalies that allow for bypass of enteric contents, including air, into more distal bowel, thereby creating a gas pattern aptly described as double bubble with distal gas.