I have been dealing with Bartholin cysts for 2 years and just recently figured out I have an RV fistula. It was the gas coming out of my vagina that was the tell tale sign. This last event was so upsetting - I had the geyser you speak of plus anal leakage and my entire vaginal/perinium area was inflamed. My OBGYN gave me a script for Amoxycillin until I get seen by the CRS. That made life so much better. I had tried some Flagyl that I still had and it did nothing for the vaginal issues. NO more geyser, no more vaginal inflammation. The Flagyl works on other areas I guess. I'm going for an MRI this week or next. I'm not sure if I want to do a seton after everything I've read.