I feel your pain. My 3.5 yo DS has the pee thing down cold, but he still poops in his underwear. I WISH he would ask for a Pull Up! But, no, he poops in his underwear and then tells me, "I think I pooped in my underwear." It is kind of funny, but I try to be kind of neutral about the whole thing. We just go to the bathroom and dump the poo in the potty, clean him up and put on new underwear. Sometimes he poops three times a day, so this can be quite a pain in the neck (and a lot of poopy underwear)! But, I'm trying not to put too much pressure on him (we do mention that it will be so great to poop on the potty, etc, but I just try not to mention it too much), so he doesn't end up constipated. He did successfully pop on the potty a few times, but it isn't consistent. Like I said, I feel your pain.