Gastrointestinal bleeding of undetermined origin: What diagnostic strategy to propose?

Gastrointestinal bleeding of undetermined origin (GBUO) is defined as gastrointestinal bleeding without an identified cause or location despite an endoscopic assessment including an esogastroduodenal endoscopy (EOGD) and a total colonoscopy. A distinction is made between exteriorized GBUO and non-exteriorized occult GBUO. The causes in the majority of cases (vascular, inflammatory and tumoral) are located in the small intestine. The diagnostic strategy aiming to locate the origin of the GBUO is a real challenge. Innovation in endoscopic and imaging techniques has enabled minimally invasive exploration of the small intestine. In Europe, there is a strong consensus to recommend a video-capsule endoscopy (VCE) as the first-intention study. If there is reason to suspect intestinal obstruction, VCE is contraindicated and a CT-enteroscopy is then performed as first intention. Enteroscopy is performed as a second-line treatment, either for therapeutic purposes after a positive VCE or CT-enteroclysis, or for diagnostic purposes after a negative VCE. Finally, intraoperative enteroscopy (IOE) coupled with surgical exploration should be reserved either for therapeutic purposes in the event of impossibility or failure of preoperative enteroscopy, or for diagnostic purposes in the event of recurrent GBUO after failure of all other studies and explorations of the small intestine.