Kidney Stones!

This morning, usual one, where I was giving Riaan a shower before getting him ready for school. I left the bathroom for a few seconds and let him 'practice' showering himself. When I returned, he was busy spraying water into his mouth, gulping it and making LOUD BURPS! I said to him, "Riaan stop drinking the bath water..its bad for you"...... His prompt revert, "But Mumma, I have to drink lots of water, else I will get kidney stones" ! ....Need I tell you my horror! (he says he learned that at school)