Patients with a ureteral or kidney stone that causes symptoms, like pain, frequently have small kidney stones that don't cause symptoms. If these small kidney stones are determined to be asymptomatic (not causing any problems or pain), then most urologists will simply remove the symptomatic ureteral stone and leave the additional stones in the kidneys. However, symptomatic kidney stones started as small stones that didn't cause symptoms. This means that the small stones remaining in the patient's kidney may cause problems later. The purpose of our research is to test if removing small stones from the kidney prevents future stone episodes.

Inclusion Criteria:

• Scheduled to undergo surgery (URS or PCNL) for a primary stone.
• Computed tomography (CT) exam within the 90-day pre-operative period
• Small (≤ 6mm) asymptomatic stones in visible on KUB or CT (i.e., calcium stones) in the contralateral kidney for a primary renal stone or ipsilateral kidney for primary ureteral stone.
• Recurrent (having had previous stones) or multiple (simultaneous bilateral stones) stones
• Able to give informed consent
• Age 21 years or older

Exclusion Criteria:

• Inability to give informed consent
• Age less than 21 years
• Stones not visible on KUB or CT
• Patients with systemic disease or renal anatomical disorders (RTA, primary hyperparathyroidism, sarcoidosis, enteric hyperoxaluria, medullary sponge kidney)
• Any condition (eg, psychiatric illness) or situation that, in the investigator's opinion, could put the
• subject at significant risk, confound the study results, or interfere significantly with the subject's
• participation in the study.
• Unwilling to participate.