I would only suspect pouchitis if Mema is getting up due to urgency or going to the restroom, which she has not indicated to be the case. Pouchitis never disrupted my sleep unless it was awakening me to use the restroom. Of course I have sleep issues regardless of Pouch function but unless I have urgency attendant to pouchitis, I wouldn’t be suspecting something Pouch related as opposed to non Pouch related.
I would also note that untreated sleep apnea in persons over the age 65 can and frequently does lead to strokes. It’s not something you want to happen if it doesn’t need to, and it’s also something that is easy to rule out, or rule in, without guessing.