Need potty training help!

My daughter just turned 3 this month. We’ve been working on potty training for several months, and she’s pretty good with peeing. But poop is another issue.

She tried not to poop at all for a while, which culminated in a huge poop in the potty after being constipated. She was kind of traumatized, and it irritated her bum as well. Now she’s physically healed, but she still won’t poop in the potty. She just waits until she can’t hold it in and then goes in her underwear.

To make things worse, she’s been sent home from daycare twice this week for “diarrhea” in her underwear, which is actually semi-formed stool. I believe it’s a consequence of her withholding, and not illness, but we can’t just have her stay home/get sent home every other day- my partner and I both work and take care of a baby.

I have no idea how to handle this!