RESUMEN
Petersen's space hernia [PSH] is a well-known complication of laparoscopic roux-en-Y gastric bypass [LRYGB] in up to 7% of cases. This led the surgeons to close this defect during surgery. We report the case of a young lady, 25 years old with a body mass index [BMI] of 55 kg/m[2] who had LRYGB in October 2004 with antecolic roux limb, without closing the Petersen's space [PS]. Two years later she presented with vague abdominal complaints, which drew our attention to the occurrence of this type of internal bowel herniation through the PS. routine laboratory investigation and upper endoscopy failed to reveal the problem. However, computerized tomography [CT] scan of the abdomen showed one of the major signs of internal herniation, namely, rotation by 180 degrees of the superior mesenteric vein [SMV] counterclockwise upon the superior mesenteric artery [SMA]. This hernia was reduced surgically through small laparotomy wound after a failed trial to do it laparoscopically. The PS defect was repaired and closed