My son was the same way. He is almost 3-1/2 and did not want to even try sitting on the potty to poop. He would pee all of the time, but when it came to poop, it would only be in his pullup. We started to tell him that after Christmas, he would have to poop on the potty. He would repeat it to us and even tell total strangers that he was going to poop on the potty after Chrismtas. (very cute!). When it came time, he was just about to go in his diaper and I pretty much carried him in to the bathroom, screaming at me, but told him in a stern voice that it was time. He pooped and then cried. The second time, he did the same thing, cried all the way to the potty, but then seemed excited afterwards. We made a huge deal out of it, called Grandma, and gave him a reward (matchbox cars). It seemed that each time, he was only upset for a few minutes while sitting there, but then got excited because "it wasn't yucky" and he got a car afterwards. Now he goes everytime. He still has accidents when he pees, but so far, no poop in the underpants. Maybe just bite the bullet and physically put him on the potty when you see him starting to go in his diaper. He might be upset the first few times, but maybe figure out that it's actually easier. Good luck! I know it's frustrating, and all kids are different. Jen S.