My 24 month old son has mastered toilet training at home, took 2 weeks, but refuses to empty at school. They were trying to put him on the toilet every two hrs and he would get very upset. Now he is refusing to go. I told the staff to back down and let him tell them, but he has held for 8 hours, 3 days in a row. Dry even through naps. He is also refusing water at school or only takes sips. They can't use his home toilet at school due to health codes. An article by a urologist online wrote this was dangerous and is going to damage his bladder or cause UTIs, which the school mentioned. Any truth? Suggestions?