No Crohn’s but not sure what’s going on

@Derrick - It's not such a gray area really.  For instance it is no longer said that removal of the colon "cures" ulcerative colitis as had been the standard advice before J-pouch became the "gold standard" surgery.   Most  j-pouchers end up with pouchitis at some point - not Crohn's.  Sometimes there is what's referred to as "backwash" inflammation that occurs upstream of the pouch.  Here is a good article. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8239975/

"Cuffitis" is a separate condition and is treated with topical application of mesalamine.  If you search "cuffitis" on this site you'll find plenty of stories.

As I posted in your other thread, I have been in the same "gray area" as you for almost 20 years. You say that they don't think you have Crohn's - but they don't know if you do, either. But whether you do or not DOES NOT MATTER. You, I and thousands of others will live the rest of our lives in this so called gray area and the sooner you accept that, and focus on treating your inflammation, the better off you will be, physically and mentally.

It's most likely pouchitis due to backwash stool, but regardless of that, you have to treat it. And it is treatable with various things also including fiber and diet as well as meds.

BTW my diagnosis is EXACTLY the same as yours except for one difference- my cuff is clean. I have a very small cuff- my surgeon did this intentionally because my colon had dysplasia when removed. His work in that regard has been complimented by my GIs. Not sure if that's why my cuff is OK. All my issues are at or above the inlet.

There is a likelihood that in time you will need to go on biological drugs, as antibiotics over time, even if rotated aggressively, slowly lose their effectiveness. In my case after 20 years.