Retroperitoneal perforation of a duodenal diverticulum containing a large enterolith after Roux-en-Y bypass and cholecystectomy.

Roux-en-Y gastric bypass (RYGB) is one of the most frequently performed bariatric procedures worldwide. The postoperative incidence of cholelithiasis after RYGB is higher than in the general population (30% vs. 2-5%), because the altered anatomy may lead to impaired gallbladder motility and biliary stasis. We report the case of a 47-year-old female who presented 9 years after RYGB and cholecystectomy with acute pain in the upper abdomen because of a retroperitoneal perforation of a duodenal diverticulum. Intraoperatively, a huge enterolith was found in the diverticulum and removed via duodenotomy. We claim that the stone grew during the sober states as the bile accumulated locally, because the gall bladder has already been removed and no duodenal food passage remained. This acute and life-threatening situation was successfully managed by operation. Consequently, a duodenal diverticulum has to be considered as a possible but very rare complication after RYGB and cholecystectomy.