So I'm not quite sure what you're question is here, but I'll try to input my knowledge anyhow!
I've been tested for C-diff multiple times. You basically just do a stool sample. I've tested positive twice. IMO, as long as you nip it in the bud, it is treated rather easily. I went on a dose of "special" antibiotics, basically they were like $600 pills that wouldn't upset my stomach and made sure the infection was gone. (However, I live in Canada and my pills were covered so I ended up only paying a few cents. This might not be an option for you).