Fat-reduced diet in the treatment of hyperoxaluria in patients with ileopathy.

Thirteen patients with ileopathy were studied under metabolic ward conditions, first on a 100-g fat diet and later on a 40-g fat diet. Ten of the patients were studied after three to 27 months on a fat-reduced diet. Ten of the patients had a high urinary oxalate excretion on the high-fat diet compared with a control group. The patients with a faecal fat output of more than 15 g a day showed a reduction in oxalate excretion when the fat intake was decreased and in the follow-up study the oxalate excretion was low in all patients except in one with a remaining steatorrhoea. There was a correlation between urinary oxalate excretion and faecal output of fatty acids. It is postulated that a low intraluminal calcium ion concentration, mainly caused by the high fatty acid content, explains the hyperoxaluria. The low fat diet, which also reduced the diarrhoea and increased the urinary output, was acceptable to the patients. The diet is recommended for patients with ileopathy in order to reduce the risk of formation of renal calculi.