Up to 5% of patients with recurrent gastrointestinal (GI) bleeding remain undiagnosed by EGD and colonoscopy, the presumed source of bleeding in these patients being the small intestine. These patients fall under the category of "obscure gastrointestinal bleeding," and frequently require an extensive diagnostic work-up. For these reasons, most patients who present with obscure or occult gastrointestinal bleeding typically undergo multiple endoscopic evaluations, including capsule endoscopy and various radiologic imaging studies, including enteroclysis, small bowel series, CT scan, angiography, and radionuclide scan. Recently, many centers (included the Brigham and Women's Hospital) have begun using capsule endoscopy and CT enterography (CTE) for evaluation of suspected small bowel pathology. This is an observational study enrolling patients referred to the Brigham and Women's Hospital for obscure gastrointestinal bleeding designed to compare the diagnostic yield of various diagnostic modalities, in particular capsule endoscopy and CT enterography in the evaluation of obscure gastrointestinal bleeding.