www.nlm.nih.gov http://www.nlm.nih.gov/medlineplus/ency/article/003590.htm http://www.nlm.nih.gov/medlineplus/ency/article/003590.htm Stool C. difficile toxin http://www.nlm.nih.gov/medlineplus/ency/article/003590.htm http://www.nlm.nih.gov/medlineplus/ency/article/003590.htm