This case is of a 45-year-old female with a remote history of roux-en-y gastric bypass presenting with an obstruction. Several months prior to presentation, she was having abdominal pain and underwent an exploratory laparotomy at an outside hospital. She was found to have a Petersen’s hernia which was repaired.


Current work up included a CT which showed no evidence of a bowel obstruction and esophagogastroduodenoscopy (EGD) which was unremarkable and revealed a healthy gastrojejunal anastomosis with a normal roux limb. She then had a drop in her hemoglobin from 12 to 7.5. She underwent repeat EGD which showed roux limb congestion, friable mucosa with hemorrhagic appearance and ulceration. Biopsies showed superficial necrosis. She was then transferred for escalation of care and further work up was unremarkable.


Because she was having continued symptoms despite comprehensive work up, she was taken to the operating room for a diagnostic laparoscopy. Upon entering her abdomen, there was evidence of twisted mesentery. A significant portion of her small bowel had herniated through a defect in the mesentery and the bowel was run in an attempt to identify each limb of the bypass. The roux limb was run proximally from the jejunojejunostomy and a large mesenteric defect in Petersen’s space was identified.


This patient was likely having intermittent obstructions due to internal herniation. The roux limb was likely intermittently twisting and becoming ischemic manifesting as abdominal pain. Because the defect was so large, the twisting would eventually self-resolve leading to a diagnostic dilemma.