Role of occult blood loss in anaemia after partial gastrectomy.

The present investigation is a study of occult gastrointestinal blood loss in 20 anaemic postgastrectomy patients and 14 control subjects. One patient in the postgastrectomy group was found to be bleeding from undetected haemorrhoids. One patient in each group showed sensitivity to aspirin with greatly increased occult blood loss. The mean blood loss in 18 postgastrectomy patients with unexplained anaemia was 0.6 +/- 0.5 ml/day compared with 0.5 +/- 0.5 ml/day in 13 control subjects. Only two of the 19 anaemic postgastrectomy patients studied lost more than 2 ml blood/day. Aspirin blood loss in 18 postgastrectomy patients was 2.4 +/- 2.1 ml/day, compared with 2.6 +/- 2.7 ml/day in 13 controls. The pattern of aspirin blood loss is identical in both groups. All gastric biopsies obtained from nine patients with Polya gastrectomies showed changes of gastritis; some showed complete gastric atrophy and intestinal metaplasia. Occult gastrointestinal bleeding is not an important factor in the pathogenesis of anaemia after partial gastrectomy unless there is either stomal ulceration or a lesion completely unrelated to the partial gastrectomy. If occult bleeding is present after partial gastrectomy a careful search for the site of bleeding is indicated. Excessive intake of aspirin or increased sensitivity to aspirin was not shown to be a significant factor in the pathogenesis of the anaemia in this group of patients. However, because of the inability to augment iron absorption to compensate for blood loss, it would be inadvisable for the patient with a partial gastrectomy to take a high dosage of aspirin for long periods of time, unless aspirin-induced blood loss is measured and shown to be very low. Aspirin administered in low dosage is not contraindicated after partial gastrectomy.