Duodenal Volvulus due to Duodenum Inversum.

Duodenum inversum, or inverted duodenum, is a rare congenital disorder resulting in an abnormal position of the third and/or fourth portions of the duodenum. Most patients are asymptomatic, but others can experience pain, nausea, vomiting, peptic ulcer disease, pancreatitis, and even intestinal obstruction. In this case, we report a patient who presented with acute abdominal pain and vomiting. He was diagnosed with duodenal volvulus and obstruction due to duodenum inversum. After failing nonoperative management, the patient was successfully treated with surgical resection.