SAFF, I'm guessing you meant to write that the local treatments *haven't* helped. Hopefully you've given them enough time (at least a couple of weeks) and considered combinations of them.
One wacky idea that you'd really need GI guidance for would be to use Flagyl gel, which is intended for vaginal use, applied rectally. I'm sure there's no research on this, so you (and your doctor) would be flying blind. Taking it orally isn't likely to get where it's needed. Good luck!