The incidence of urinary tract calculi after small-intestinal bypass operations for treatment of obesity.

Jejunoileal bypass operations have been used for more than 20 years for the treatment of massive obesity. This treatment results in malabsorption with diarrhoea, especially during the first year after the operation. A high incidence of urinary tract calculi have been found in these patients (4, 5, 15, 19, 24). Other known late complications are transient disturbances in liver function and electrolyte balance (5).