what's the best way to keep my daughter's pull up on at night?! she removes pants because of a…

what's the best way to keep my daughter's pull up on at night?! she removes pants because of a sensory issue with clothes so that doesn't work....and she somehow figured out how to get her sleepers off without unzippering them. we just bought her a new bed to sleep in and I walked in to find her bed covered in poop and she was playing in it. I'm desperate...