[Retrogastric colon mimicking foramen of Winslow hernia or left paraduodenal hernia: case report].

We report the case of a 54-year-old woman who developed epigastralgia and vomit. Because of the abnormal gas in the epigastrium on abdominal X-ray, ileus due to foramen of Winslow hernia or left paraduodenal hernia was suspected. However, abdominal CT and barium study revealed the gas in the epigastrium to be the air in the transverse colon interposed between the stomach and pancreatic body. This anomalous interposition of the transverse colon is called retrogastric colon. The ileus was due to non-specific inflammatory duodenal stenosis. It is important to prevent misdiagnosis of retrogastric colon as lesser sac pathologic condition such as abscess, bowel perforation and internal hernia.