DS, 2yrs 8mths, has been dry for about 7 weeks. He got the wee thing within a couple of days of potty training (he's even dry most nights!). He struggled with poo thing from the start but seemed to be getting it (with help and lots of asking). In the last few weeks, however, he's pooing in his pants for every poo and he's very defiant about it. He appears to know he's doing it but wont tell us. When asked by us, he SMILES and says yes he's done a poo (he often adds 'I must do it in my pants'. We've tried everything I can think of - giving of treats, withdrawal of treats, star charts and even shouting at him (whoops). Has anyone else encountered this/have any suggestions? Thanks in advance.