ReviewThe role of the 24-h urine collection in the management of nephrolithiasis

•Recurrent stone formers should have a full metabolic evaluation including serum chemistries and 24- hour urine collection(s).•Maintaining urine flow rates above 2.5 l/day reduces risk of formation for all stone types.•Hypercalciuria is very common in stone formers and is influenced by calcium, sodium, and protein intake.•Uric acid stone risk is greatest at low urine pH and calcium phosphate stone risk at higher pH values.

Recurrent nephrolithiasis is a common chronic condition that is often preventable with dietary modification and pharmacologic therapy. Patients with recurrent kidney stones should have a metabolic evaluation, consisting of radiologic studies to assess stone burden, crystallographic stone analysis, and laboratory studies including standard serum chemistries and 24 h urine collection(s). This article focuses on the interpretation of urine chemistries to identify lithogenic risk factors and assess the contribution of diet to the formation of kidney stones.