What is the most effective preventive strategy to reduce recurrence of renal stones?

• A. Increase hydration
• B. Early treatment of urinary tract infection
• C. Limitation of calcium intake
• D. Use of probenecid

Answer: (A)

Raising urine volume to dilute the urine is the most effective general strategy to prevent stone recurrence. When you drink more fluids, the urine becomes more dilute and the concentration of stone-forming salts (such as calcium, oxalate, phosphate, and uric acid) drops. Lower solute concentration reduces the likelihood that these substances will crystallize and form stones, slowing or preventing new stones from developing. This simple, safe, and widely applicable approach helps across most stone types, making it the cornerstone of long-term prevention.

Early treatment of a urinary tract infection is important for stones formed by infection (struvite stones) because those stones can be driven by bacteria, but hydration remains the overarching preventative measure for most stone types. Limiting calcium intake is not recommended and can, in fact, increase the risk of calcium oxalate stones by altering gut absorption and urinary chemistry. Probenecid is not a standard preventive therapy for stones; it affects uric acid handling but isn’t used as a primary prevention strategy for stone recurrence.