Dr. Hibberd's answer:

 

Kidney stone development at a young age confers a very high risk for recurrence. Your grandson will have more stones unless he is able to prevent their formation. He should have a urologist evaluate him and arrange for stone analysis and stone risk testing to see what measures are best to use.

 

In the meantime, he should avoid dehydration and be sure he drinks plenty of water — eight glasses per day or more. Some supplements and vitamins may increase stone formation, so eliminate these until the stone analysis is done. Tea and soft drinks are major causes of trouble, so be sure he lays off of them and is not consuming excess calcium in his diet until the stone analysis can be done.