Hey H.,
Okay, so here's my opinion: don't push the potty training. I don't know if you've asked him if he wants to wear pull-ups again, but I'd tell him, in a loving way, that if he can't poop on the potty, you'll have to put him in pull-ups again. I'd say, "You don't have to poop on the potty right now if you don't want to. I'd really like for you to, and I think once you get the hang of it, you'll want to, too. But if you really don't want to, you don't have to. However, poopy underwear is really pretty gross to clean up, and I am going to insist that you wear pull-ups until you decide you'd like to try the potty again." He might be relieved. There will be people who tell you-"don't go backwards-he'll never poop on the potty until he leaves home for college..." but I think that's a bunch of malarkey. Kids all learn, or decide, to potty train at different times. My daughter wasn't trained until she was 3 and a half. We encouraged her, I got mad a couple of times-did potty treats, the sticker chart,etc...and then I just let it go. I stopped being ticked that she wasn't using the potty on my time schedule, and I swear that once I relaxed, she did, too. Was it an overnight Christmas miracle? Nooooooo. But, honestly, she made the decision to go on the toity once and for all and that was it-straight to night-time panties! I can't promise you that this will work for you, but I'd give it a try. Why be stressed out about it, unless you think there really is something physically wrong with him? My completely uneducated guess is he's probably fine. There are kids that aren't completely potty-trained until they're 5, God bless their mothers, and it's a mind-over-matter thing. Bigger battles to fight, my dear. Just act from a place of love and compassion, take a deep breath when you're changing his pull-ups (though, not directly over the pull-up in question) and give him a chance to make the decision for himself. If it doesn't work, what have you lost? If it does, you gain an empowered little guy who's proud of his accomplishment, because it is truly his.
Good Luck, sister,
Al