Metabolic evaluation and medical therapy for stone formation.

There is little debate that nephrolithiasis is an increasing problem for public health. In the USA, the treatment of renal stone disease costs more than two billion dollars per year. The lack of prospective randomized trials reflects the problem of subjecting stone-formers to prospective studies and placebo treatment, and studies often use a single-group design. Nevertheless, investigation of metabolic abnormalities often makes the identification of an etiologic factor, and consequent treatment, possible, and stone formation can be reduced.