Which of the following represents two nutritional strategies to reduce the risk of calcium-oxalate nephrolithiasis in short bowel syndrome?

• A. Adequate hydration to urine output > 1200 mL/day only
• B. Adequate hydration to urine output > 1200 mL/day and oral calcium supplements 800-1200 mg/day in divided doses not exceeding 500 mg per dose
• C. Oral calcium supplements 800-1200 mg/day with no hydration
• D. Low-fluid intake and calcium restriction

Answer: (B)

In short bowel syndrome, reducing calcium oxalate stone risk comes from keeping urine dilute and lowering intestinal oxalate absorption by binding oxalate in the gut. Drinking enough fluids to achieve urine output over about 1.2 liters per day helps prevent stone formation by diluting stone-forming solutes. At the same time, taking calcium supplements 800–1200 mg per day in divided doses (no more than 500 mg per dose) allows calcium to bind dietary oxalate in the gut, forming insoluble calcium oxalate that is excreted in stool rather than absorbed and then excreted in urine. Taking calcium with meals enhances this binding effect.

The other options either emphasize only one strategy or combine an approach that can worsen risk (such as low hydration or calcium restriction). Therefore, the combination of adequate hydration plus divided-dose calcium supplementation best addresses both urine concentration and oxalate absorption.