Gastrointestinal blood loss in patients with chronic renal failure.

In the management of patients with chronic failure one of the persistent medical problems is that of anemia. Since iron deficiency can be an important component of this anemia, this study was designed to evaluate the possible contribution of gastrointestinal blood loss to their anemia. Blood loss was quantitated by 51 chromium labeling red cells in normals and in patients with chronic renal failure both before and during chronic hemodialysis. Four normal volunteers had a gastrointestinal blood loss of 0.83 ml/day, six azotemic patients not yet on hemodialysis had significantly greater gastrointestinal blood loss of 3.15 ml/day (p less than 0.05). Ten patients on chronic regular hemodialysis had a daily gastrointestinal blood loss of 6.27 ml/day which was significantly greater than both the normals (p less than 0.01) and the predialysis azotemic patients (p less than 0.05). Complete gastrointestinal tract evaluation in the chronic dialysis patients revealed several upper gastrointestinal tract mucosal abnormalities although discrete bleeding sites were not identified. In conclusion, azotemic patients both before and after chronic hemodialysis have increased gastrointestinal blood loss. This increased blood loss contributes to the increased iron loss in this patient population.