People who can get rid of c-diff are lucky. I tried a couple of different antibiotics to get rid of mine and it wasn't going away. The doctors were a little stunned that nothing was happening and they had me see the colorectal team. The c-diff had infected my colon so bad that I had to have emergency surgery to remove my colon and then I had a colostomy bag for 9 months.
The thing with c-diff is that you can pick it up from anywhere, especially in the hospital. CFers are normally on a lot of antibiotics and being on so many antibiotics can kill the "good" bacteria in your intestines that keeps c-diff away. Then, in order to treat it, they have to put you on another antibiotic, which in my case, didn't work.
Since I no longer have my large intestine/colon I am on probiotics to try to keep c-diff away. Thankfully it has worked so far. It was recommended that I take three capsules per day and that's what I do. Anyway, c-diff sucks and it's hard to stay away from.
Another thing, there is a new treatment out there (don't know how often it has been performed) and what they do is take a relatives poo, filter it out to just get the "juices" from it (which carries the good bacteria), and then transplant it into the person who has c-diff (through a tube going down the infected person's throat). I know that this sounds gross, but I guess that it's been an effective form of treatment for c-diff. I would have definitely gone with this treatment if it was available to me because then I would have avoided 3 surgeries.