Hi Christine are you still around to chat?
This actually is extremely common so don't despair I guarantee that Maddie will learn to put her poops in the potty at some point.
What is it about pooping that makes little kids reluctant to sit onto of a huge hole that makes a loud noise when flushed and who knows where it goes? Most kids feel quite vulnerable at this point and there can be an element of fear even though there doesn't appear to be.
She has pooped all her life lying down or standing up so the transition to sitting which you very astutely recognize is what is hanging her up it hard!
As you have lasted 4 days do not give in and give her a pullup. Her poop will come out. Even if not in the potty it is an advance from the pullup. Play LOTS of squatting on the floor games...maybe even let her be naked on top of some towels in case she feels that something is coming out. Why don't you think about a touch of laxative? Miralax is now over the counter and is a tasteless odorless, textureless osmotic laxative that works very well....As no stool has come out in 4 days you can bet it may be a bit hard so you can also lubricate the area with lots of Vaseline.
even on the inside a bit.
If she were to hold it much longer AND you feed she is uncomfortable...not eating...belly distended and painful...consider using an enema which really you want to avoid if possible as she will hate it. Make time daily for enormous amounts of exercise and feed her her favorite meals that you know she will eat a lot of. Expect the urge to poop (when you will see her squeezing everything together to make it not come out) after meals about 1/2 hr. If you can convince her to potty sit then this would be ideal. Continue with the prizes and the rewards....I like a treasure chest of $ toys that is visible and stocked....Or stickers of her favorite characters....
Try your best not to get frustrated as I don't believe she is doing this to manipulate you at all....she is just strong willed and scared....thus it is all about her. Make sure you give her lots of praise on how brave she is and how you know she can accomplish anything before it happens. Her fear is not in any way rational.
And thus can't be explained away. You can also try the bathtub if you don't mind her pooping in there and she gets so uncomfortable after a meal that she is screaming....allowing her to release her poop in there and letting her see nothing happens is a step in the right direction.
I had a potty training resister as well....I won't share the way we finally got her to pee as I'm not proud of it!! but suffice to say it involved threatening to some degree....and I did the poop the same way...I just ran out of diapers and said I wasn't buying anymore. She lasted 2 days and did plenty of witholding and dancing but the stool mass gets to a point where you can't hold it in anymore and thus it will come out. She now a year later has #1 no memory of using diapers or of the techniques we used to get her to train and has never had an accident probably cause she trained so late.
Thus I would encourage you to remain patient as you have time on your side now. Giving in to a pullup will mean that the next time you try she will hold more than 4 days! You may have already gone to bed and in the am I hope you are blessed with a poop that comes out after breakfast. I am located in Spain and thus there is a time difference of 6 hrs ahead of ecoast and 9 ahead of west. If you would like to respond please do so! If you feel that I have helped to answer your question please click on the accept button. Thanks!
Another idea is blowing bubbles while on the toilet...to make her bear down...