Medical history of your child is suggestive of predisposition for a recurrent stone formation. Commonly, a child would complain of an abdominal/or flank pain, occasionally presenting with high grade fever related to urinary tract infection resulting from an obstructing stone but many times may remain asymptomatic before being incidentally diagnosed with a kidney stone. To find the cause of the stone formation, one would need to review the child’s history including family history of kidney stone formation, looking for any evidence of kidney/urinary tract structural anomalies predisposing to stone formation and most importantly, seeking any evidence of metabolic disorders. Metabolic disorders could result in an abnormal excretion of various mineral salts into the urine, which could lead to recurrent stone formation. Hence to exactly find the cause and type of stone being formed, your child would require extensive lab work-up including 24-hour urine studies to quantitify the amount of various minerals salts like calcium, oxalate, uric acid, phosphate and cystine. Also included in the evaluation would be blood tests to check for the levels of various minerals as stated above and if possible to undertake a chemical analysis of a passed kidney stone. All these would help to identify the stone composition and predisposing factors towards the stone formation and accordingly offer certain medication intervention intended to prevent recurrent stone formation. Lastly, daily intake of >1.5 litres of fluid and low salt diet are known to reduce the chances of recurrent stone formation. I would recommend an evaluation by an urologist for your child for the continued care for the recurrent stone formation.