I had C.diff this past summer (now no infection for the past 7 months- but had 3 recurrent cases of it.) By the 3rd case, my infectious disease doctor put me on a 3 month prescription for Vancomycin. I had had it for the first case but the c.diff just returned. Next the 2nd case medicine didn't work even though it was VERY expensive for just the co-pay - I was very weak from some other medical complications.) But this time, I had the Vancomycin 4 times a day for 2 week, then 3 a day for a week, then twice a day for a week, then 1 a day for a week, then the rest were 1 every other day and then 1 every third day till they were gone. The whole thing took about 3 months but it was finally gone although I had to work to get strength etc. back. (I might have the exact timetable a little off because it was so long ago, but you get the dwindling idea - there were something like 111 pills.
I just went for what I considered my last appointment (just for final questions) 4 days ago. I asked what I should do if I had some serious medical problem that they wanted to use antibiotics on me for. She said to let them know I had C.diff and have them call her office because she wanted me on Vancomycin at the same time as having antibiotics. (She says i will always be prone to get it again even though I have been over the infection for 7 months now. She told me I'd be prone for the rest of my life - staying in good health would be the best way to keep it from coming back and to stay on my probiotic daily.)
Ask your doctor what you should do if they tell you that you absolutely need antibiotics. You can mention what my doctor said, but your doctor may say something different. And, if you don't have an infectious disease doctor, I'd suggest trying to get one. If there is a hospital near you, they might have infectious disease doctors on their staff. I got mine because I was in the hospital. I found out that other doctors don't have much knowledge about it. My infectious diease doctor told me they just started paying much closer attention to it about 10 or so years ago when they saw it causing major problems so the information on it is still in flux.
This was a little lengthy, but I hope it helped.
God bless you (I did a lot of praying getting over mine - I am 76 and it is a little scarey at that age.)