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Evaluation of suspected small bowel bleeding (formerly obscure gastrointestinal bleeding)

David Cave, MD, PhD
Section Editor
John R Saltzman, MD, FACP, FACG, FASGE, AGAF
Deputy Editor
Anne C Travis, MD, MSc, FACG, AGAF


Bleeding from the small bowel is uncommon, but it is responsible for the majority of patients with gastrointestinal bleeding that persists or recurs without an obvious etiology after upper endoscopy, colonoscopy, and, possibly, radiologic evaluation of the small bowel [1]. In the past, if no source of bleeding was found after an endoscopic evaluation, the bleeding was referred to as being "obscure." However, more recently, it has been proposed that the term obscure only be used if patients have not had a source of bleeding identified after a thorough examination of the entire gastrointestinal tract, including the small bowel [2]. Most cases of what was previously referred to as obscure bleeding are more correctly categorized as suspected small bowel bleeding.

Small bowel bleeding may either be occult or overt:

Occult bleeding refers to a positive fecal occult blood test result that may or may not be associated with iron deficiency anemia when there is no evidence of visible blood loss to the patient or clinician.

Overt bleeding refers to bleeding that is visible to the patient or clinician. Overt bleeding may manifest as hematemesis, melena, or hematochezia.

The evaluation of patients with suspected small bowel bleeding will be reviewed here. The initial evaluation of patients with gastrointestinal bleeding is discussed separately. (See "Evaluation of occult gastrointestinal bleeding" and "Approach to acute upper gastrointestinal bleeding in adults" and "Approach to acute lower gastrointestinal bleeding in adults".)

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Literature review current through: Nov 2017. | This topic last updated: Dec 17, 2015.
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