My daughter (UC) had C.diff last year. Couldn't tolerate Flagyl. After starting Vanco within 2 days everything got controlled.
Few things to follow if you can- Cut down all sugary stuff. Add plenty of good yogurt/probiotic if you can tolerate/or used to it..
C.diff can be very hard to eliminate for some. The best effective treatment so far proven is Fecal transplant. We did this for our daughter after the 1st round of Vanco as we want to avoid further vanco course in case if it pops up again.
Lots of info on the effectiveness of fecal transplant for C.diff on you tube and medical journals. check it out...