Abstract
A total of 258 patients with obscure gastrointestinal bleeding were referred for small bowel enteroscopy, a procedure which allows endoscopic evaluation of most of the small intestine. A small bowel tumour was found in 5% of patients. In 50% of patients no diagnosis could be made, but when the cause of obscure bleeding was discovered small bowel tumours were the single most common lesion in patients younger than 50 years. Small bowel tumours causing gastrointestinal bleeding may remain undetected despite extensive diagnostic evaluation. We conclude that small bowel tumours are the most common cause of obscure gastrointestinal bleeding in patients less than 50 years of age. Small bowel enteroscopy is diagnostic of small bowel tumours even when all previous diagnostic studies, including enteroclysis and angiography, are negative.