Turmeric (active ingredient: curcumin). 40 U.S. studies are looking at turmeric as a potential inhibitor of C difficile. A turmeric enema may equal vancomycin for C. difficile colitis. Dr. Rattan Patel and his research team found that growth of all strains of C. Difficile was inhibited (in vitro) by extracts of regular grocery store turmeric, at concentrations that would be easily obtained in the colon by adding the spice to food or consuming it in capsule form. Taken orally for therapeutic use, you would need a high quality extract. Dr. Patel maintains that 4 g/day of curcumin achieves a concentration of curcumin in the stool well above the concentrations that inhibited C. difficile growth.
Mercola.com offers an excellent turmeric extract
Iodine. Will kill C-difficile spores.
Grapefruit seed extract (GSE)
Grapefruit Seed Extract -"Medicine Chest in a Bottle"
Wild Oregano Oil (WOO)