My son is 3 almost 4, he is totally potty trained with urination, but he is refusing to go on the potty to move his bowels. He will hold it in all day long if he has to. The only way that he will go is if he finds a pull up in the house (i know throw them away) and he will take off his underwear and put on the pull up to go poop. I have put him on the potty to go but he cries and holds his stomach and refuses to go. He has often just gone in his underwear. My husband says it's scary for him , like losing a part of himself, i suppose. The only thing that i can't understand is that on 2 occassions he pooped in the potty 2x when I was in the other room. Is he holding on to his infancy or am I overanalyzing.