...you might want to consider taking one of the brands people are recommending PLUS another like Florastor for its Saccharomyces boulardii. This is a particular strain of beneficial bacteria that has been proven it studies to help fight the recurrence of C.diff infections. Read what Wiki says here....scroll down to "Recurrent C.diff infection":
Some doctors will write a prescript
ion for Florastor, or you can just google "saccharomyces boulardii" and lots of different brands will come up. Best I can tell, S.boulardii does not come in a combo probiotic with other strains--at least I've never seen it that way.
I make yogurt and we use different brands of probiotics--VSL#3, Theralac, Solaray, Dr. Michael Murray's...to name a few. They say it's good to have one with lactobacillus acidophilus as a main strain in combination with several other strains. Also, try to find one with at LEAST 10 billion cfu. Good luck!