Well, poop! At wits end!

My guess is that she might sometimes find defecating difficult and she
associates that with the current box (and possibly even with your
bathroom area).

I suggest trying this: place a second box in your kitchen or other
area *away from* your bathroom. If you're concerned about cleaning up
stool, put a plastic carpet runner or long rug under/near that box for
easier clean up. See if she defecates in that box. Also make sure it
has a very low side, even if you need to cut another section away of a
traditional litter box.

Rene

I do agree with your opinions, it's really a good and flexible job....
Very well said, thanks for sharing.