Urolithiasis after intestinal bypass for morbid obesity.

Urinary calculi, predominantly of oxalate composition, have been noted in 10 to 14% of a large series of morbidly obese patients after jejunoileal intestinal bypass at this institution. Physical and metabolic changes after bypass surgery, including the presence of hyderoxaluria, hyperuricemia, and fluid and electrolyte disturbances are reviewed in their possible relationship to this increased incidence of urolithiasis.