Any good toilet training methods for my 3 year old boy? He knows how to tell us if he wants to pee, but when it comes to pooing, he will hide and poo, then tell me with a 'sorry mummy, I pooed'...

My friend's son is also the same, will only not poo in potty. You can try whichever that works for him. Does he need to be alone when pooing? Does he need to read a book? A comfort item to help him relax, could be a favorite stuffed animal or toy? Don't forget to be generous with your praises and encouragement once he poo in the potty! Be patience with him, I'm sure he will get it one day.