DS was 4 in June, as much as we tried we could not get him potty trained until February when we decided to just take him out of nappies during the day. We had a full week od constant accidents then it finally hit home.
BUT he has not done 1 poo in the toilet or potty he would always wait until nighttime when he got his pull ups on. So about 2 weeks ago we decided again to just remove them and see how he was, we have'nt had one wet accident but he is either pooing in his trousers and it's falling out the leg or directly on the floor! Everyday we generally wake up to hunt the poo
but the most frustrating thing is he knows what to do!
He has been spoken to, shouted at, smacked on the bottom (not hard), had full explanations of why he has to do it in toilet, bribes and even threats of no Santa 
His room is right next to ours and also the bathroom and we leave the light on all night so he does'nt get scared and we leave the small toilet seat on too but nothing seems to be working. Anyone else had this? how do you deal with it?