Mummy2Eve, it sounds so warped but is so nice to find someone in same situation!
At nursery he poo's in pants, only goes twice a week but I think there is plenty of opportunity for him to find a quiet spot and do it, they have been fine about it and said that it will just happen one day that he 'gets it' and will then always do it in toilet.
He has been brilliant with wee's, we do have the odd bad day which I find really frustrating as I know how good he can be, but I can deal with that. (Do get a bit anxious if we are going out for the day though or somewhere where I know it will be a bit difficult, we're going to the Zoo on Sunday for the day for example, and I am already having toilet related nightmares)!
He used to just carry on playing after poo'ing his pants but now he does come and say, really sheepishly, that he's poo'd.
He says to me quite often that he has to do wee's and poo's in the toilet and send them to poo land so I do think he wants to do it, on the way to nursery this morning I said, "Remember if you want a wee to go and do it in the toilet" and he replied, "Yes, mummy and poo poo's in the toilet too".
I have tried being blase and got no where and tried being firm (not shouting) and got nowhere, tried the treats and got nowhere! Yesterday, and I am totally ashamed to admit this before everyone starts beating me with a stick, when it happened for the 2nd time that day and he walked to the downstairs loo and told me what he had done, I fell to my knee's and pretend cried, he came over to me instantly to cuddle me (I am cringing as I type this!!!) and I just said to him, really calmly and quietly, that I so wanted him to be able to do poo's in the toilet like mummy and daddy and it made me sad that he couldn't and I really wanted to help him. I gave him big cuddles back and have since felt horrendous guilt, just wish someone had a magic cure!
I know everyone keeps saying he will get it, and my rational head knows he will, but I have read so much about children who are 5 and 6 and are still having poo issues that have become more and more deep rooted due to issues at DS's approx age and I am starting to get fanatical that he is going to be seeing some child psychologist about it!