Introduction: Morbid obesity, defined as a body mass index (BMI) of over 40 kg/m2, is globally an imminent health threat. Conservative therapies do often not yield the desired result. Bariatric surgery includes several interventions that are performed on patients with morbid obesity, like gastric bypass surgery. The number of bariatric surgeries annually is estimated to be around 500,000 worldwide; about half of these are gastric bypass surgeries. In the Netherlands, the most common performed bariatric intervention is the Roux-en-Y gastric bypass (RYGB). An important long-term complication of this surgery is internal herniation, a condition in which a part of the GI tract is herniated through an opening in the mesentery made during RYGB surgery. Incidence of internal herniation is 1-5%. Conventional abdominal CT examination is often not conclusive about the presence of internal herniation. When internal herniation is clinically highly suspected after abdominal CT examination (but not necessarily confirmed), the patient is subjected to diagnostic laparoscopic surgery. Unfortunately, a negative abdominal CT scan does not exclude internal herniation in all patients. This pleads for the development or exploitation of alternative techniques that might aid in the diagnosis of complications after RYGB surgery. Since the anatomy of GI tract is altered when internal herniation is present, visualizing the mesenteric vasculature may aid in the diagnosis of this complication after RYGB surgery. This study aims to confirm the feasibility and superiority of diagnosing internal herniation using CT examination of the mesenteric arteries over conventional CT examination.