I agree with JenandJeh--- daytime vs nighttime training--totally different
and the "pushing" them will only make them more freaked out. It sounds like you've tried all of the rewards. One thing that helped my older one was the Potty time elmo video---I know it sounds silly, but it did. And also a "big" piece of candy--so something they normally don't get (like even a fun size candy bar type of thing rather than a few M&Ms).
The other thing is that once they actually poop in their big boy undies--they'll not like that and remember to go on the potty. Yes, it'll be a mess--but I bet it only happens once. I definitely recommend going right to big boy undies rather than pull-ups. That is what we ended up doing for both boys and it worked great. The pull ups only enabled them--and was good practice for pulling up/down--but reality is that they don't really "learn" from them.
Oh--and I know this sounds dumb but because he picked out his fave undies (characters)--I remind him that Jake and the neverland pirates do NOT want him to poop on them.....he laughed but I think it actually helped.
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