If the size of the stone is small, it’s usually treated with ESWL in which shock waves are given from outside and stone breaks into small pieces. On the other hand, if the stone
is quite big, then the surgical removal
of the stone
is a better option. Please do continue to drink lots of water for it does facilitate at least in preventing the formation of new stones if not the flushing out of the present stones.
I sincerely hope that helps. Take care.