I know, it's bizarre. Maybe it's not due to the Tylenol, but I have noticed on previous occasions that my pouch would be irritated for a day or two if I took NyQuil one night. But of course it could also be due to activation of my immune system to fight the flu. I've had colds over the years, but they've never triggered a pouchitis episode.
I now assume that I've developed some deficit in barrier function, which has allowed the bacteria in the pouch to get down to the epithelial cells, triggering an immune response. Antibiotics may kill off the bacteria, but will the barrier heal? That's the big question.
Had chronic pouchitis from 2010-2013, then was pouchitis-free from 2013-2017.