Doctors who aren’t familiar with J-pouches sometimes have no idea that long-term antibiotic treatment is a reasonable choice. If they can’t be educated (e.g. by handing them a journal article) then it may be necessary to find a more knowledgeable gastroenterologist.
My doctor was more open minded, and we learned together. He actually gave me a copy of a review article about pouchitis, but I had to point out to him that the article suggested that combination antibiotic therapy may be necessary - he just hadn’t read it carefully enough.