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Stewardship of GI Tests
Diagnostic Stewardship of Syndromic Tests for Gastrointestinal Infections

Released: August 11, 2025

Trevor Van Schooneveld
Trevor Van Schooneveld, MD, FSHEA, FACP, FIDSA
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Key Takeaways
  • GI infection syndromic testing can significantly improve patient outcomes if used and interpreted appropriately; however, inappropriate use can lead to overtreatment, particularly for C. difficile.
  • GI infection syndromic panels target community-acquired pathogens and are not ideal for use in an inpatient setting; mini syndromic panels were created to narrow down the list of bacterial pathogens to those that are most relevant and are an alternative to full panel testing.

A key aspect to consider with GI infection syndromic testing assays is diagnostic stewardship: ensuring the right test is used for the right patient. The inappropriate use of these highly sensitive panels can result in overtreatment. However, when used appropriately in people who meet the criteria for testing, I think they can improve patient outcomes.

Diagnostic Stewardship and C. difficile Infection
The data on Clostridium difficile testing are clear: molecular testing is highly sensitive but alone does not identify clinically significant C. difficile infection (CDI). This coupled with financial penalties imposed on hospitals for high rates of CDI has resulted in significant interest in diagnostic stewardship around GI syndromic testing.

Both the Infectious Diseases Society of America/Society for Healthcare Epidemiology of America guidelines and the American College of Gastroenterology guidelines for diagnosis and treatment of C. difficile recommend coupling molecular testing with a toxin assay. In addition, many laboratories have implemented restrictions on C. difficile molecular tests requiring confirmation that the patient is not receiving laxatives as well as clinical findings suggestive of CDI such as documentation of diarrhea and elevated white blood cell count.

Knowing When to Use a GI Pathogen Panel
The clinical setting is an important factor in determining the utility of a GI pathogen panel, and I have found that the panels are not ideal for use in evaluating hospital onset diarrhea. At my institution, we restricted the use of GI pathogen panels for inpatients after 3 days in the hospital. The rationale was that most pathogens on the panel are community acquired, and it is highly unlikely that a patient would acquire Salmonella or Shigella within the hospital. If the healthcare professional (HCP) felt the panel was needed outside of this window they could contact the microbiology director and discuss whether molecular testing is appropriate. For patients who needed C. difficile testing we had a recommended use of a C. difficile–specific test and not a panel. 

We also do not allow HCPs to repeat the GI syndromic panels. These panels are highly sensitive and repeat testing is likely to provide the same result as the initial test. 

One question that often arises is whether molecular testing can be used to document the clearance of pathogens for people who work in food service or high-risk healthcare settings that require this before returning to work. These molecular panels are not an appropriate method to document clearance because they cannot distinguish between the genetic material of live and dead pathogens and thus may return positive results for weeks after a pathogen has been cleared. For patients who need a document of clearance, traditional culture methods should be used in consultation with your local lab.

The Utility of Mini Syndromic Panels
I think there is a real debate about whether testing for every pathogen in the larger panels is meaningful and necessary. Some laboratories do not report some of the results from the larger panels when they do not consider them meaningful. For example, the relevance of Enteropathogenic E. coli strains, particularly when found with other enteric pathogens, is unclear and treatment is rarely indicated.

In response to the surplus of information provided by the full syndromic panel, mini syndromic panels were created to narrow down the list of bacterial pathogens. These mini panels tailor detection to pathogens that are most relevant in treating GI infections, and may provide a targeted alternative to the full panel that is more straightforward to interpret. If HCPs are  using these smaller panels they should be aware of what is and is not included as if the panel doesn’t reveal a diagnosis they may need to order additional testing.

Your Thoughts
What questions do you have about the diagnostic stewardship of GI infection syndromic panels?

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