Welcome to HealingWell, Robin. I'm not sure if any of our little ones have dealt with c. diff. You may want to visit this site, which is devoted to parents of children with IBD and its complications:
http://www.dragonpack.com/ibdsupport/parents/
I hope your little guy is feeling better very soon. C. diff can be really hard to clear up, unfortunately. Keep us posted, and we'll keep your son in our prayers.