Silent angiodysplasia and occult haemobilia as rare but treatable causes of refractory iron deficiency--two case reports.

Once menorrhagia has been excluded in females then, in both sexes, the gastrointestinal tract remains the commonest site for haemorrhage. This may be of surprisingly large volume but intermittent and therefore not universally demonstrated on stool testing. However, if loss is persistent it may nevertheless culminate in absolute iron deficiency and thus, even when occult blood is not present on repeated examinations, quantitation using chromium labelled red cells becomes invaluable. In this situation, endoscopy or contrast radiology of the small and large bowel may fail to reveal any lesion even when these procedures are repeated or used in combination. Modifications by direct inspection or camera study may be helpful in improving diagnostic accuracy. It is nevertheless practical, as illustrated by these two cases, to more widely recognise the value of radionuclide scanning methods. In one this was due to unsuspected haemobilia and the second to major duodenal vascular malformation although it could be reasonably argued that initial recourse to angiography might have demonstrated this. The principle is that when precisely defined anatomically surgery can be elective and limited as a result of careful proactive planning and operations likely to have a high initial rate of success. The role of nuclear medicine in the investigative algorithm of such patient is re-emphasised. Thus, in any individual with unexplained but proven absolute iron deficiency failure to reveal the cause by first screening with gastroscopy and colonoscopy or barium studies including the small bowel should not automatically be repeated. Rather, the blood loss needs to be documented and, if possible, subsequent evaluation moved to advancement or push enteroscopy, capsule endoscopy or the more invasive angiography only once quantity a pattern of bleeding are defined by radioisoptic imaging.