This is really, really minor. I think it's more of a curoiusity than anything else at this point. I have been sitting comfotably all day and hardly notice it. It's not nearly as bad as yours, Val, and doesn't deserve such as scary name as fistula. Minifist is much more appropriate.
To get it taken care of I will have an office appointment and the dr will give it a little snip there--at least he better. He may just remove the skin tag as that will take care of the problem.
I could do it myself, but not nearly as well as a person with the proper tools who is not hunched over in a weird position trying to operate while squatting over a mirror. Imagine that pose.