The natural history of renal and ureteric calculi.

In a prolonged follow-up of a series of 416 patients at The London Hospital Stone Clinic it was found that recurrence could still occur even as long as 10 years after the first stone, though this risk decrease slowly year by year. Recurrence is seldom related to hypercalciuria or urinary infection except when infection is caused by or associated with B. proteus in women. Claims for the value of any form of therapy for stone disease must be evaluated against the background of the natural history of lithiasis.