[Effect of diet on lithogenic and inhibitory substances in the urine].

A standard diet is the pre-condition for an accurate investigation of the causes of stone formation reasons in recurrent stone-formers, since the uncontrolled influences of individual diets on the composition of the urine can thus be eliminated. In patients kept on a standardized diet intake a steady state (balance of excretion of lithogenic substances) is obtained after about 5 to 7 days. Because it must be assumed that brief excretion and concentration peaks are very much more frequently the cause of nucleation, the determination of the circadian rhythm of lithogenic substances is most important. On the basis of our investigation results, an "investigation programme in stages" for research into the causes of stone formation is recommended.