[Perforated duodenal ulcer in a Roux-en-Y gastric bypass operated patient can be a diagnostic challenge].

Roux-en-Y gastric bypass (RYGBP) is an increasingly used procedure when treating morbid obesity. Due to the extensive gastrointestinal rearrangement, diagnostic evaluation of patients with gastric bypass and acute abdominal pain can be difficult. We present a case of a perforated duodenal ulcer in a RYGBP operated patient, where free abdominal fluid, but hardly any pneumoperitoneum was seen on a computed tomography. Free intraperitoneal fluid is an important finding and should give suspicion of the need for emergency surgery in RYGBP operated patients with abdominal pain.