Role of the laboratory in investigations of Clostridium difficile diarrhea.

The laboratory diagnosis of acute diarrhea due to Clostridium difficile can be based solely on the demonstration of either cytotoxin or enterotoxin in the stool. This and other noncultural methods, however, fail to provide isolates from which useful data can be obtained. Outbreaks can be recognized only by comparison of isolated strains. A dual approach of toxin detection and isolation is therefore recommended.