Repeat Stool Testing to Diagnose Clostridium difficile Infection Using Enzyme Immunoassay Does Not Increase Diagnostic Yield

In patients who had multiple stool samples tested for CDI by EIA, almost 91% were accurately diagnosed based on the results of a single stool sample alone. Subsequent testing yielded a positive result in only 8.6% of patients. We therefore recommend that repeat testing not be done on a routine basis because it does not significantly improve diagnostic yield.