“…The chemical composition of the stone should always be identified, preferably by infrared spectroscopy or X-ray diffraction (7,8). In patients at high risk of recurrence, an individualized metabolic assessment is required, including: measurements of blood levels of creatinine, sodium, potassium, chloride, calcium (ionized or total corrected for albumin), phosphate and uric acid; measurement of urine pH and urine specific gravity; 24-hour urine collection with measurement of urine volume and concentration of calcium, oxalate, uric acid, citrate, sodium and magnesium (7,8).…”