Gastrointestinal bleeding of obscure origin undetected by multiple tests for fecal occult blood and diagnosed only by capsule endoscopy: a case report.

The term gastrointestinal bleeding of obscure origin is used to describe bleeding of unknown origin that persists or recurs after a negative initial esophagogastroduodenoscopy and colonoscopy. We report the case of a middle-aged woman with gastrointestinal bleeding of obscure origin who had 9 stool specimens that tested negative for occult blood but was found to have adenocarcinoma of the distal duodenum on capsule endoscopy. This case illustrates that, in the presence of unexplained iron-deficiency anemia, multiple negative fecal occult blood tests do not exclude the presence of GI blood loss, and that capsule endoscopy is a valuable diagnostic study in this context.