Clostridium difficile is a Gram-positive spore-forming anaerobic bacillus found in the environment. Its spores are part of the colonic flora in about 2 to 3% of healthy adults, with colonization rates increasing during hospitalization to 20 to 40%. Disease occurs when the organism shifts to its replicating vegetative form with toxin (A and B) production, this typically happening when there is inhibition of the competing colonic flora by antibiotics. ...