I want medical research that shows a colonoscopy does not induce or cause risk for c diff. The prep does a number on your system. My doc wants me to also do a penicillin challenge to see if I am still allergic as I was as a child. It requires me to actually take 500 mg of it. His point is that penicillin has less risk of c diff than other antibiotics. What if that causes c diff? It did for my friend who had c diff again. He scares me every time is see him and I don’t need that reminder about how bad it’ll diff is.