Bernard J, et al. - This study seeks to identify the relationship between daily water intake and 24-hour urine volume among adolescents with nephrolithiasis in order to calculate a “fluid prescription,” the additional water intake needed to increase urine volume to a target goal. Researchers performed a secondary analysis of an ecological momentary assessment study that prospectively assessed daily water intake of 25 adolescents with nephrolithiasis over 7 days. During 12 months of the study period, 22 individuals completed fifty-seven 24-hour urine collections. They distinguished 24-hour urine volumes obtained for clinical care within 12 months of water intake measurement. This analysis utilized a linear regression model to calculate the magnitude of the association between daily water intake and 24-hour urine volume, adjusting for age, sex, race, and daily temperature. Results demonstrated that the fluid prescription equation (FP = dUOP)/0.71), which reflects the association between water intake and urine volume, could be applied to support adolescents with nephrolithiasis achieve urine output goals to reduce stone recurrence.