Anonymous wrote:OP here - yes, I'm sure the move did upset her, and we've had a new baby since we moved. It is most likely her way of letting me know these things are not okay with her. But that's not why I am seeking help - I can't move us back to our old house and I can't send the baby back. She's going to have to get over it. I just wish I knew how to stop her from doing it.
You're assuming that she's pooping outside of the box on purpose. It's far more likely that she's constipated (which could be a result of being upset).
People always assume a cat going outside of the box is behavioral or them "telling us something." But usually, initially going outside of the box is connected to a medical/health problem. Then later, they associate the box with the pain of the health problem. But in the beginning, it's usually a medical problem. It's likely just coincidence it happened when it did.
I would take her to the vet and try treating her for constipation. Vets usually prescribe either the hairball cream or lactulose. But I found neither to be helpful. Miralax is the only thing that worked. It's actually commonly prescribed to cats in Canada who have megacolon. Ask your vet if it is okay to try a sprinkle.