Urolithiasis in patients with a jejunoileal bypass.

Five hundred and seventeen patients who had a jejunoileal bypass performed at the University of Minnesota Hospitals were studied with regard to the formation of urinary calculi postoperatively. A 9 per cent incidence of stones was found in the 365 patients for whom complete data were available. Men were affected more commonly than women. Of particular note was the correlation between long term oral supplementation of calcium postoperatively and a delay in the onset of symptomatic urolithiasis. A group of 91 recent patients who have been maintained on orally administered calcium are stone-free as long as 12 months after operation, again suggesting that supplementation of calcium may help prevent urolithiasis in patients who have had a bypass procedure.