3 years and 4 months ds understands about going to the toilet, and if he wears nothing on his bottom half he'll take himself off to the toilet, so we know he's got the control. As soon as he has a nappy on he will wee and poo in it, he freaks out when it's time to change him, and underpants are a no go zone, he won't entertain them at! Sticker chart don't work, rewards don't work - anybody out there got any advice please, we are struggling with trying to understand and find a way around this!