High Fluid Intake Alone Ineffective in Preventing Stone Recurrence: Lancet

A new study published in The Lancet revealed that an intervention promoting sustained high fluid intake did not reduce symptomatic urinary stone recurrence in patients with prior stone disease. Despite the 24-hour urine volume increased in both groups and being higher in the intervention group at multiple time points, this did not translate into clinical benefit. The findings suggest that additional preventive strategies beyond high fluid intake are needed.

This randomized clinical trial enrolled 1,658 participants aged 12 years and older with a history of urinary stone disease and low 24-hour urine volume across 6 academic medical centers in the US. Participants were randomly assigned to either an intervention group or a control group who received standard guideline-based care. The study examined whether a multicomponent intervention could help patients maintain higher fluid intake in preventing urinary stone formation.

The intervention combined several strategies like personalized fluid prescriptions, financial incentives for meeting hydration goals, health coaching to address barriers, and optional tools like reminder text messages. The goal was to create sustained behavioral change over a two-year follow-up period.

Towards the end, the results showed little difference between the two groups in terms of the symptomatic kidney stone recurrence. Events such as stone passage or the need for medical procedures occurred in 19% of participants in the intervention group when compared to 20% in the control group, a difference that was not statistically significant.

The participants in the intervention group consistently showed higher 24-hour urine volumes at multiple checkpoints throughout the study, which indicated better adherence to hydration goals. Despite this improvement, the increased fluid intake did not translate into meaningful clinical benefits. Secondary outcomes (new stone formation, growth of existing stones, and composite measures of recurrence) also showed no significant differences between groups.

The participants receiving the behavioral program reported more urinary symptoms such as frequency, urgency, and nighttime urination during the first year, though these differences diminished over time. Also, a small number of individuals in the intervention group developed asymptomatic low sodium levels (hyponatremia), though no cases required hospitalization. While hydration remains a cornerstone of prevention, the findings suggest that simply increasing fluid intake may not be sufficient to significantly reduce recurrence risk.

Reference:

Desai, A. C., Maalouf, N. M., Harper, J. D., Sivalingam, S., Lieske, J. C., Lai, H. H., Reese, P. P., Wessells, H., Yang, H., Al-Khalidi, H. R., Kirkali, Z., Tasian, G. E., Scales, C. D., Jr, & Urinary Stone Disease Network Investigators. (2026). Prevention of urinary stones with hydration: a randomised clinical trial of an adherence intervention. Lancet, 407(10534), 1171–1181. https://doi.org/10.1016/S0140-6736(25)02637-6