"Antibiotic-dependent pouchitis" just means that the pouchitis can't be controlled without continuous (or nearly continuous) antibiotic therapy. Folks whose pouchitis is sensitive to a variety of antibiotics usually rotate between several different antibiotic choices, switching to the next one in rotation every week or two. This is thought to reduce or prevent the development of antibiotic resistance by the gut bacteria. Some folks here have done this for decades. Some of us have fewer choices of antibiotics that work, though. I've been on Cipro for six or seven years. A couple of years ago it became less effective, but adding Flagyl to the Cipro fixed it right up, even though Flagyl alone had never been effective for me.

Obviously you can run out of options, either because of unacceptable side effects or loss of efficacy. So far I'm doing fine, as you probably will for a good long while. I suggest you share with your doctor (and read) the article in the post at the very top of the Pouchitis Forum here. Good luck!

Another thing to understand is that you do not become immune to antibiotics. Bacteria that is exposed constantly to antibiotics can become resistant to them by mutating to adapt to them. This is why they can lose effectiveness and why rotating antibiotics or taking them intermittently is favored. 

How long does this take? It varies. It can be decades, years, or months. Or, it may not occur at all. 

If you are lucky, perhaps a long course of 4-6 weeks will cause a asting remission.

Jan