Thanks for the input ladies.

His poos are nice and loose now. It was only a problem for that week but the pain has been seared into his little brain. I have tried the rewarding with stickers and lollies and also reading a book. These methods were used to get him back on for wees but if I even try to take him near the toilet for a poo he freaks out. I have a feeling that this one is just going to take time. I have had one poo in the potty but I think that was an accident as he went to wee and then came and got me really confused to look in the potty. We made a really big fuss of him when he didn?t but haven?t managed to get him to do it again yet. That was about 6 weeks ago now.