PURPOSE OF THE REVIEW: Review tests available for detection of Clostridium 
difficile (C. Diff) induced disease, including when such tests should be done in 
children and how they should be interpreted.
RECENT FINDINGS: Multiple tests are available for detecting disease due to C. 
diff. These include colonoscopy and stool analysis. Colonoscopy with biopsy is 
the most sensitive test for detecting the presence of colitis. The toxins 
produced by the C. diff. (toxin A, toxin B, and binary toxin) are the agents 
that cause injury and disease. Only toxin producing C. diff. Strains will cause 
disease. Binary toxin by itself is not thought to produce disease. Binary toxin 
causes disease in humans when present with toxin A and B producing bacteria, and 
has been implicated with fulminant life threatening disease. Stool analyses vary 
in sensitivity and specificity depending on the assay used. The presence of 
toxin producing strains of C diff. in the stool does not equate with disease. 
The presence of a toxin-producing bacteria or toxins (A or B) only equates with 
disease if diarrhea or a diseased colon (toxic megacolon, ileus, and sepsis) is 
present. Nucleic acid amplification testing (NAAT), when used in the stool from 
patients with diarrhea, appears to be the most efficient study to detect the 
gene that encodes for toxin A and B and thus to diagnose C. diff.-induced 
disease. Infants have a high carriage rate of C. diff. and are believed not to 
develop disease from it or its toxins. Infants should not be tested for C. 
difficile. The NAAT is most specific when done on patients with diarrhea with 
liquid stools. Testing for C. difficile should only be done on patients with 
diarrhea. One can assume that a patient who has no diarrhea and is not ill does 
not have C. diff.-induced disease. Treatment should be limited to patients with 
diarrhea who test positive for C. diff. toxin (A or B) or toxin-producing 
bacteria. Direct testing for binary toxin is not commercially available. Binary 
toxin is only thought to cause disease in humans when C. diff. toxin (A and 
B)-producing bacteria are present.