Obscure digestive bleeding is defined as recurrent bleeding for which no definite source has been identified by routine endoscopic or barium studies. Mucosal vascular abnormality or 'angioectasia' is the most common course of obscure bleeding, especially in elderly patients. Small bowel tumours are more frequent in patients younger than 50 years. However, missed or underestimated upper and lower gastrointestinal lesions at the initial endoscopic investigation may be the source of a so-called obscure intestinal bleeding. The various radiological procedures, including enteroclysis, visceral angiography and CT scan as well as radioisotope bleeding scans have limitations in the case of obscure gastrointestinal bleeding. Recent developments in magnetic resonance imaging are promising. The different methods of enteroscopy have a similar diagnostic yield, reaching approximately 40-65%. Endoscopic cauterization of small bowel angioectasias seems to be efficacious but randomized trials are needed. Efficacy of hormonal therapy is very controversial. The extent of diagnostic and therapeutic strategies must be based on a number of factors including the patient's parameters, bleeding characteristics and also the result of previous work-up.
Copyright 2001 Harcourt Publishers Ltd.