[Suspicion of anemia-inducing gastrointestinal bleeding: how far should assessment go?].

In a retrospective evaluation of 362 patients with iron deficiency anemia or visible blood loss from the gastrointestinal tract (hematemesis or melena), the bleeding source could not be found in 18% of cases (66 patients) even by extensive gastrointestinal endoscopy. In these cases neither small bowel studies nor repetitive endoscopic examinations increased the diagnostic yield. On the other hand, gastrointestinal endoscopy resulted in the diagnosis of gastrointestinal malignancy in 25 cases, most of whom could be resected curatively. The fecal occult-blood test was positive in 85% of the cancer patients, indicating the usefulness of this test as a diagnostic tool. If the bleeding source remains obscure in spite of extensive gastrointestinal endoscopy and gastrointestinal malignancy has been excluded, further investigation by small bowel studies or angiography is unrewarding and only indicated in selected cases.