We present a 38-year-old male patient with no past history of interest who came to the emergency department with syncopal symptoms accompanied by a melanic-rectorrhagic stool. Examination: conscious and oriented, BP 106/68 mmHg, abdomen soft and depressible, positive rectal examination for haematic debris. The blood test showed a CBC of 30%, then 23% and a urea level of 67 mg/dl. A gastroscopy was performed, which was normal, and a colonoscopy up to the cecum and terminal ileum showed incipient angiodysplastic lesions of the colon and rectum. A capsule endoscopy was requested, which showed no pathological findings, and subsequently a Tc99m-pertechnetate scan showed the existence of a focal hyperactive area in the right iliac fossa adjacent to the right iliac artery suggestive of the existence of ectopic gastric mucosa compatible with Meckel's diverticulum in that location. It was decided to operate under general anaesthesia with a Mc Burney incision, observing a Meckel's diverticulum 60 cm from the ileocaecal valve with a wide base (> 50% of the surface of the intestinal diameter) and inflammatory signs. Intestinal resection was performed, including the diverticulum and a mechanical latero-lateral anastomosis plus prophylactic appendectomy. The postoperative period was uneventful and he was discharged on the 5th day. No blood transfusion was required. The pathological anatomy reported Meckel's diverticulum with heterotopic gastric mucosa.