Although urinary tract calculi, often associated with hyperoxaluria, occur commonly following small intestinal bypass surgery for obesity,1-5 renal failure is not a recognized complication of intestinal bypass procedures.1-10 The patient whose case is described in this report had normal renal function prior to small intestinal bypass but developed progressive renal insufficiency, with hyperoxaluria and calcium oxalate nephrocalcinosis, after bypass. After surgical restoration of bowel continuity, renal function stabilized and urinary oxalate excretion fell to normal.
A 41-year-old man underwent jejunoileal bypass (14 inches of proximal jejunum end-to-side to 4 inches of terminal ileum) in June 1971 at another hospital. He had no antecedent history of renal disease and the preoperative serum area nitrogen level was 12 mg/100 ml. After surgery, he lost approximately 40 kg (88 lb) in two years; his weight then stabilized at approximately 90 kg (198 lb) although diarrhea continued. In August