Jonathan Harper, MD, on the importance of fluid intake for reducing stone recurrence

In this video, Jonathan D. Harper, MD, discusses findings from the PUSH trial examining how changes in 24-hour urine volume may affect urinary stone recurrence¹ and how the results can inform hydration counseling. Harper is a professor of urology at the University of Washington in Seattle.

Results from the PUSH trial were presented at the 2026 American Urological Association Annual Meeting in Washington, DC. The analysis included 1461 adult participants.

Data showed that those who increased their 24-hour urine volume by more than the median increase of 438 mL/day had a 24% lower odds of symptomatic or radiographic stone recurrence at 2 years compared with those who did not (OR, 0.76; 95% CI, 0.59 to 0.98; P = .04), after adjustment for baseline characteristics. Participants who maintained higher urine volumes from baseline through follow-up also had a 49% lower risk of symptomatic stone recurrence (HR, 0.51; 95% CI, 0.31 to 0.83; P < .01) and a 33% lower risk of symptomatic and/or radiographic stone recurrence (adjusted OR, 0.67; 95% CI, 0.51 to 0.87; P < .01) compared with those who maintained lower volumes.

Harper emphasizes that the findings may allow clinicians to set more achievable hydration goals for patients who struggle to reach the guideline-based target of 2.5 L of urine per day.

“Maybe we don't give [patients] such a high, unrealistic goal,” he said. We can say ‘Start out trying to drink 20 ounces more fluid a day’, and that'll increase their urine output probably by about those 15 ounces of urine that this study showed reduced recurrence. So I think that's really important for patients.”

He also cautions against interpreting the findings as evidence that fluid intake is unimportant, noting that the results instead highlight the difficulty many patients face in achieving recommended fluid intake levels.

REFERENCE

1. Harper J, Lieske J, Desai A, et al. Urine volume and urine osmolality and risk of recurrent stone events: results from the prevention of urinary stones with hydration (PUSH) trial. J Urol. 2026;215(5S2):e6. doi:10.1097/01.JU.0001192572.07890.f8.13