Oxalate, Quant, 24-Hour Urine

Patients who form calcium oxalate kidney stones appear to absorb and excrete a higher portion of dietary oxalate in urine than do normals. Hyperoxaluria is not uncommon in subjects with malabsorption. Twenty-four hour urine collections for oxalate are indicated in patients with surgical loss of distal small intestine, especially those with Crohn's disease. The incidence of nephrolithiasis in patients who have inflammatory bowel disease is 2.6% to 10%.¹ Hyperoxaluria is regularly present after jejunoileal bypass for morbid obesity; such patients may develop nephrolithiasis. Used to work up nephrolithiasis.