My eldest son will be 3 in march and has been out of nappies since he was 2 1/2 but won't poo!! He waits until he has his pull ups on at night and then goes. He knows what he's doing but just will not go on the potty. I've tried everything. Got him reading on the potty, got pirate petes potty training which he know off by heart, had sticker charts... Anyone got any other ideas? Had thought about taking him out of his pull ups at night too but don't want to distress him. Help!