<p><strong>RATIONALE &amp; OBJECTIVE: </strong>Although maintaining high fluid intake is an effective, low-risk intervention for the secondary prevention of urinary stone disease (USD), many stone patients do not increase their fluid intake.</p>

<p><strong>STUDY DESIGN: </strong>We describe the rationale and design of the Prevention of Urinary Stones with Hydration (PUSH) study, a randomized trial of a multi-component behavioral intervention program to increase and maintain high fluid intake. Participants are randomized (1:1 ratio) to intervention or control arm. The target sample size is 1642 participants.</p>

<p><strong>SETTING &amp; PARTICIPANTS: </strong>Adults and adolescents ≥12 years of age with a symptomatic stone history and low urine volume are eligible. Exclusion criteria include infectious or monogenic causes of USD and comorbid conditions precluding increased fluid intake.</p>

<p><strong>INTERVENTIONS: </strong>All participants receive usual care and a smart water bottle and smartphone application. Participants in the intervention arm receive a fluid intake prescription and an adaptive program of behavioral interventions, including financial incentives, structured problem solving, and other automated adherence interventions. Control arm participants receive guideline-based fluid instructions.</p>

<p><strong>OUTCOMES: </strong>The primary endpoint is recurrence of a symptomatic stone over 24-months of follow-up. Secondary endpoints include changes in radiographic stone burden, 24-hour urine output, and urinary symptoms.</p>

<p><strong>LIMITATIONS: </strong>Periodic 24-hour urine volumes may not fully reflect daily behavior.</p>

<p><strong>CONCLUSIONS: </strong>With its highly novel features, the PUSH study will address an important healthcare problem.</p>