I had c.diff., and I can tell you it is horrible. Took me a year to get back to my normal diet. I wish someone had told me that yogurt and even kefir is not enough. You need some good probiotics. I like Culturelle and some acidolopholus pearls because they tend to be easy on your stomach, but you can't take them at the same time as you take your anti-biotic. So if you take the anti-biotic morning and night, then you'd take the probiotics in the middle of the day. Otherwise, the anti-biotics kill off all of the good "bugs" you just put in. Florastor is a good yeast, which is not killed off by anti-biotics, but it is hard on my stomach. Some people tolerate it just fine, though. Also, continue taking the probiotics for a few weeks after you stop the anti-biotics to rebuild your flora.