Does anyone have any advice for me.... My son is 2 1/2 and is out of nappies in the day, but he will only do a poo in his nappy! I have tried all tactics and reward systems to get him to do it on potty or toilet, but he ends up constipated if I don't put a nappy on him. He asks for a nappy on to 'do a poo' and can get very upset if I ask him to do it on the toilet or potty.... Any idea??