Hi S.
Boy, does this bring back memories! My son was almost 4 before he decided to poop in the toliet instead of in his pants. I couldn't afford the pullups, if I wanted to and finally got to the place that I got tired of being the one who cleaned the poop. My son was at least 3 and 1/2 and I knew he knew WHAT to do, he just refused. He really just didn't want to take the time.
I would offer him time in the morning before/ then after breakfast for time to sit on the potty. He never had to go then, I just thought that it might stimulate things, so when later, when he was involved and playing and didn't want to take the time, it was out of the way.
I would watch for the signs of his need and then offer, that never worked either. Finally, I offered that when he needed to go poop, and decided to go in his pants that he would need to wash his underpants and pants or shorts. Before he actually did, I showed him how to wash both his underwear and pants with soap and water and do exactly what I had been doing for over a year. Then when he pooped the next time, I then had him stay with me, while I redemonstrated the procedure. I wasn't angry or upset and just explained this is what HE would be doing the next time. And then showing him again how to expertly wash HIS own hands with soap and water to make sure there wasn't anything on his hands because of the germs.
Interestingly, he actually, under my supervision, would go through this about a month and one day, came to me and said, "Mommy, I think it would be easier if I just pooped in the toliet today." I agreed with him and watched him go to the toliet and do what he knew how to do, but had refused for so long. Just as easy as pie.
When he went out to play, I remember jumping up and down, you would have thought I made a touch down, just like those crazy football players! I really had something to celebrate!
I have plenty of poop stories that are hilarious, if you feel you need a pick-me-up! I know at the time, I was discouraged and thought there must be something wrong with my training. Now, I understand, my son is very strong willed, about everything! A true leader. Have a great day and I know you'll have gotten lots of great ideas. God bless.
D.