sorry you weren't feeling well. I've been taking probiotics for years, so I've just doubled up on them since starting this Bactrim yesterday. I had to choke down my dose last night and ended up taking Benadryl because I was nauseated all night. Today when I took it, I drank two bottles of water behind it and didn't have any problems whatsoever. Maybe that's the key...or my body is adjusting to the medication. I've heard of the c-diffcial. I definitely don't want that! Probiotics are a WONDERFUL thing, aren't they???