Anand Nath,Bikram K. Paul,Mario Golocovsky,Timothy R. Shope,Timothy Koch, Unusual Cause of Acute Abdominal Pain in a Roux-en-Y Gastric Bypass Patient American Journal of Surgical Case Reports 2020 2674-5046 http://dx.doi.org/10.31487/j.AJSCR.2020.03.04 https://www.sciencerepository.org/unusual-cause-of-acute-abdominal-pain-in-a-roux-en-y_AJSCR-2020-3-104 Abstract: Abdominal pain after Roux-en-Y gastric bypass is an important potential complication. Perforation of an ulcer in the excluded duodenum is a rare occurrence in a patient who has undergone gastric bypass. We present a case of a 61-year-old female with a history of Roux-en-Y gastric bypass, who presented with acute right upper quadrant abdominal pain, which began 1 week after starting treatment with ibuprofen. The evaluation revealed tachycardia, epigastric/right upper abdominal tenderness and leukocytosis. CT abdomen without contrast, ultrasound examination and nuclear medicine scan of the gallbladder were unremarkable. Upper endoscopy revealed an ulcer just distal to her gastrojejunostomy. At exploratory laparotomy, a wellcontained perforation was identified on the anterior duodenal bulb. The perforated ulcer was debrided, the intestine closed with sutures and a drain was left in the abscess cavity. Conventional endoscopic access to bypassed duodenum and stomach is difficult after gastric bypass. In this case, the patient ingested oral ibuprofen and developed both a marginal ulceration as well as an ulceration of the excluded duodenal bulb. The latter finding is consistent with a nonsteroidal anti-inflammatory drug side-effect developing via a hematogenous exposure.Keywords: Roux-en-Y gastric bypass, bariatric surgery, duodenal ulcer, intestinal perforation, nonsteroidal anti-inflammatory agents