The small bowel as a source of gastrointestinal blood loss.

The small bowel is a rare but important source of blood loss from the gastrointestinal (GI) tract. In approximately 5% of all patients with GI bleeding, no cause for the bleeding is evident even after an extensive workup. This bleeding is often termed "gastrointestinal bleeding of obscure origin" or "obscure gastrointestinal bleed" (OGIB). Recent advancements in enteroscopy have contributed to a better understanding of the small bowel as a source of bleeding. On average, 27% of patients with OGIB have been shown to have lesions in the small bowel, with common findings including arteriovenous malformations (AVMs) and small bowel tumors. The trend in primary diagnostic workup for obscure GI bleeding or suspected small bowel lesions is shifting toward enteroscopic examination. Availability of an accessory channel now offers the clinician management options such as endoscopic injection therapy, electrocautery, and polypectomy. The "gold standard" for examination of the entire small bowel is intraoperative enteroscopy. A newer technique involving laparascopic assistance may lower the morbidity associated with this examination. Combined hormonal therapy may be an alternative treatment for patients with AVMs or an unknown cause of bleeding after enteroscopic examination.