DS has been trained - pee - for over a year. was 4 may. Has started primary school and had one accident wit poo. Wont poo at home and never did. Went to hv and she suggested just leave it and it will develop. Not a chance. He will be 4.5 shortly. Any ideas. He holds it till it is nearly in his pants and then says he needs to go. It just sits there till it drops. It - the poo - is already out. Never an accident with pee - not even at night.