Special Precautions/Comments:

Additional Information:

Renal stone disease affects approximately 5-12% of western world. Size of urinary calculi can vary from the size of a grain of sand to the size of a pebble. The exact pathophysiology of stone formation is poorly understood but risk factors include genetics, diet, drugs (e.g. allopurinol, amoxicillin), urinary tract infections (UTIs), low fluid intake and hypercalcaemia. Infrared spectrophotometric analysis of calculi can determine the stone’s composition to help identify the cause or guide treatment, particularly in recurrent stone formers. Some stones may have a mixed composition.  

Types of stones (from most to least common): 

• Calcium oxalate 
• Calcium phosphate 
• Magnesium ammonium phosphate (Struvite) 
• Uric acid stones 
• Cystine  

In recurrent stone formers, a 24 hour urine sample may also be sent for a metabolic screen to aid investigation (pH, calcium, oxalate, urate, citrate, magnesium, phosphate, cysteine).