DS1 who is 4 1/2 has just started in reception class and refuses to use the school toilets. He is going from 9am-3.30pm without a wee and refusing to drink during the schoolday. He gets hysterical`if his teachers try get him to use the toilets as a result he's absolutely desperate for a drink and a wee by the time he gets home. He makes a mess of the loo at home because he can't wait and is now regularly bedwetting as well when he was mostly dry during the summer. Any advice/suggestions on improving the situation.