Gastrointestinal bleeding due to obstruction of the superior mesenteric vein

Gastrointestinal bleeding is a common clinical symptom. Finding the underlying cause is the first step for treatment. In a few patients, this can be difficult. The present work reports on the unusual case of a 53-year-old man who presented gastrointestinal bleeding. No bleeding site was found by gastrocolonoscopy or interventional examination, but after multidisciplinary consultation, we discovered that the cause of gastrointestinal bleeding was the obstruction of the upper mesenteric vein.