My doc says it is essential to take a probiotic from day one of taking xifaxan. You have to separate the doses of antibiotic and probiotic by at least 2 hours, ideally 3. That way the probiotics do successfully form colonies in the gut.
If you do this, you'll get better results than you do just taking xifaxan alone and probiotics after.
Also, beware of using yeast based probiotics, as many people have intolerances to them. If you know you are fine, then OK, but be careful. Also, I know one person who got a systemic fungal infection from taking florastor. It's not good to take it alone, you need some bacteria with it.
I have had clostridium difficile BTW. Heed my advice!!!!