Nephrolithiasis risk factors: which statement is true for patients with short bowel syndrome?

• A. Have no remaining colon
• B. Do not maintain adequate hydration
• C. Have no remaining ileum
• D. Take 500 mg calcium 2-3 times per day

Answer: (B)

Hydration status is the key factor increasing nephrolithiasis risk in short-bowel syndrome. Large fluid losses and diarrhea common with SB lead to low urine volume, which concentrates stone-forming solutes and promotes crystal formation. While anatomical factors like whether any colon or ileum remains can influence oxalate handling (for example, colon presence can raise oxalate absorption in fat-malabsorbing states), those factors vary between patients and do not universally drive stone risk. Calcium supplementation can bind oxalate in the gut and may reduce absorption, so taking calcium isn’t a risk factor and can be protective rather than harmful. Therefore, the statement about not maintaining adequate hydration correctly identifies a modifiable risk factor that increases stone risk.