Clostridium difficile is a naturally occurring bad bacteria that exists in your GI tract. In normal levels it does serve a purpose. Iodine doesn't cause c diff. The cause for the overgrow of C diff is usually Antibiotics or contamination, which in nursing is seen a lot. Usually if you take a probiotic twice a day while on any use of Antibiotics will keep the normal levels of bacteria in your GI tract to maintain a balance. Antibiotics usually kill off the good bacteria and allows for the clostridium to overgrow and take over.
We have also found a good yogurt doctors have actually been ordering their patients take who have c diff is a yogurt called Kefir. It's pretty good stuff too! Tastes good, comes in a variety of flavors! Usually available in nature section at Krogers