What is your approach to management of recurrent nephrolithiasis in patients with mixed composition uric acid and calcium phosphate stones?

Likely the urine pH is more typically low in such patients, since the uric acid components will dissolve during periods of higher pH. Consequently, the appearance of uric acid crystals in the stone suggests that the urine pH is more typically low. Drinking more fluid to cause more dilute urine always works, as Dr. @Dr. First Last pointed out. I would also look for phosphate sources in the diet (like colas) that could be eliminated and consider calcium tablets with meals rather than dairy to make...

This is a very unusual patient who clearly has 2 different etiologies for stone formation. Uric acid stones require an acid urine to form, usually a pH below 5.8. Calcium phosphate stones require an alkaline urine to form, usually a pH above 6.3. Normal urine pH is approximately 6.0. In this case, the patient's urine pH must be highly variable, remembering that a 1 unit change in urine pH equates to a 10-fold change in hydrogen ion concentration.

Ideally, each underlying condition would be treat...

Before making treatment recommendations, we need to get appropriate 24/48 hour urine collections, such as Litholink to determine what factors are precipitating the precipitation of stones.