We prospectively studied peritonitis secondary to small bowel leakage in 30 critically ill patients, each of whom had complete diversion of intestinal continuity by stoma, fistula, or both. All patients received total parenteral nutrition during implementation of the protocol. The proximal intestinal effluent was collected and recycled into the distal small bowel. During reinfusion of succus entericus, a significant reduction in the output of the proximal stoma was observed (mean 30.2%, p less than 0.001). The reinfusion also significantly reduced the volume from isolated small bowel loops in six patients (32.6%, p less than 0.001). When isotonic dialysate solution was infused into the distal intestine, a lesser though significant reduction in stoma output occurred (mean 20.3%, p less than 0.001). These findings demonstrate a consistent inhibitory effect upon upper gastrointestinal secretions by reinfusion of succus entericus. Clinical benefits of this technique include simplified control of fluid and electrolyte balance in patients with high output stomas and optimal utilization of remaining absorptive capacity for enteral nutrition.