Project Summary: Urinary Stone Disease (USD) is an increasingly prevalent and highly recurrent condition associated with major morbidity at a rising cost to society. Thus, improved management can significantly reduce its health burden. Increasing fluid intake is recommended to all USD patients. However, knowledge gaps persist regarding the impact of fluid therapy in preventing USD recurrence including effectiveness of strategies to achieve and maintain a high urine volume, and whether such strategies reduce USD recurrence. The Prevention of Urinary Stones with Hydration (PUSH) study is a randomized clinical trial investigating the impact of increased fluid intake and increased urine output on the recurrence rate of USD in adults and children. In this study 1,642 participants will be randomized to a control or intervention arm. Participants in both arms receive a “smart water bottle”. The intervention arm involves an additional program of behavioral interventions, including financial incentives, structured problem solving, and low touch interventions designed to improve adherence to a prescribed fluid intake regimen. The primary endpoint is occurrence of a stone event during a two-year observation period. The PUSH study is in its third year, and due to multiple challenges to recruitment of study participants, follow-up of participants and data collection have not yet been completed. Additional time is needed to ensure study completion and to accomplish all study goals. Although ureteral stenting is routinely performed after urological procedures for USD to mitigate peri-operative complications, stents cause significant patient discomfort. The causal mechanisms are only partly understood. The STudy to Enhance uNderstanding of sTent-associated Symptoms (STENTS) is a prospective observational cohort study enrolling adolescents and adults undergoing ureteroscopic intervention for ureteral and/or renal stones. Participants undergo detailed symptom assessment using validated questionnaires, a psychosocial assessment, quantitative sensory testing for evaluation of pain sensitization, and detailed collection of clinical and operative data. Biospecimens (blood and urine) are being collected for future research. Recruitment to the STENTS study and follow-up of the participants are expected to be completed during the original project period. However, additional time and resources are needed for analysis of collected study data. In Aim 1 of this application, the investigators will continue and complete participant enrollment for the PUSH study, continue biospecimen collection for the NIDDK Repository, analyze the data, and prepare and submit several planned manuscripts related to the study hypotheses. In Aim 2 of this applications, the investigators will analyze the data from the STENTS study, interpret findings, and disseminate findings through peer reviewed publications.