I've never heard of anyone exhibiting extreme distress from a c-diff infection in less than a day, so I doubt much that your current sypmtoms are c-diff. All of what is written above is true of c-diff, it is spread by somehow getting the c-diff spores into your gut via oral means. I'd recommend you wash your hands after using the bathroom, and anytime after being with your Aunt or at her house for a while. It might also be helpful to use some of the hand sanitizers that have springing up over the past few years. I am prone to c-diff infections myself, and my GI recommends Florastor for people combatting c-diff. Apparently the strain of bacteria in Florastor competes with the c-diff for sustenance, plus Florastor is okay to take with antibiotics because the probiotics aren't affected by the antibiotics. And no, I am not a rep for Florastor, just a satisfied customer of it for a couple of years. I hope that you don't end up getting infected. While it resembles bad cases of UC, the frequency and urgency I experienced were bewildering. If your flare continues to get worse, and you begin to notice a really bad smell to your BMs that wasn't there before, you might want to talk with your doc. Good luck to you, and I wish a speedy recovery to your Aunt. Hopefully her case will be over with one round of antibiotics, and then life resumes as usual for her and yourself.
PS I'm including a link to a c-diff support site that I belong to, much like Healingwell. Although the people in that forum are chronic sufferers of c-diff, there is a lot of good info to had there. If I'm breaking a HW rule, my apologies, let me know and it won't happen again.