Kidney stone disease: to drink or not to drink-that is the question.

Kidney stone prevention presents a paradox: an effective, safe, and inexpensive intervention-hydration-is widely recommended, yet difficult to implement in practice. The recent Prevention of Urinary Stones With Hydration (PUSH) trial by Desai et al. (n = 1658 patients) evaluated a behavioral strategy to increase fluid intake and reduce recurrence over 2 years but found no significant benefit compared with standard of care, despite modest increases in urinary volume. These results contrast with earlier trials, notably that of Borghi et al. in 1996, in which sustained urine output above 2 L/d significantly reduced stone recurrence. The limited efficacy of PUSH likely reflects insufficient adherence, with a minimal difference in urine output between active treatment and the control group, and improved baseline management in control subjects. Functional urinary symptoms and social constraints might have further hindered compliance. An important point to note is that these findings do not invalidate the protective role of increased urine volume but highlight the limitations of behavioral interventions alone. Effective prevention likely requires achieving a substantial increase in urine volume alongside comprehensive dietary and pharmacologic management.