My dfd was diagnosed with c. diff at 4 mo old. A round of vancomycin took care of it. I have to say the vanco seemed to make her feel a lot worse than the c. diff did.......she was miserable and it actually made her have blood in her pooh. Her pooh was bright green, and the smell is something like sulfery-boiled eggish-barfy. She also had never been on antibiotics, in fact she had none of the risk factors for having it.
I would highly recommend you read everything you can find on c. diff if your son is diagnosed. The spores can hang around for YEARS, so it's best to be as careful as you can with changing and diaper areas. And everyone needs to wash, wash, wash!