Effects of calcium, aluminium, magnesium and cholestyramine on hyperoxaluria in patients with jejunoileal bypass.

The urinary excretion of oxalate, calcium, magnesium and citrate as well as the inhibition of calcium oxalate crystal growth in diluted urine was studied in seven patients with hyperoxaluria following jejunoileal bypass. The study was performed on an outpatient basis before and during daily administration of 38 or 113 mmol calcium, 28 mmol of aluminum, 20 mmol of magnesium or 16 g of cholestyramine. Each substance was administered for seven days with a free interval of at least seven days. The mean urinary oxalate excretion was not reduced with any of these regimens. Administration of 38 mmol of calcium per day resulted in increased oxalate and magnesium excretion. Increased excretion of both calcium and citrate was observed during administration of 113 mmol of calcium per day. Calcium and magnesium excretion was increased with aluminium. An increased magnesium excretion was also observed during administration of magnesium, resulting in a decreased calcium/ magnesium ratio. Cholestyramine resulted in increased oxalate and decreased citrate excretion.