Core IM Hoofbeats: 43M with Diarrhea

December 4, 2018

By Cindy Fang MD, John Hwang MD, Catherine Constable MD, Marty Fried MD || Illustration by Amy Ou MD || Audio Editing by Richard Chen

Time Stamps

  1. Case [1:19]
  2. Diagnostic weight [8:42]
  3. Hypothesis driven reasoning [12:26]
  4. Anomalous clinical data [19:30]
  5. Final diagnosis [22:20]
  6. Take away points [31:21]

Human Dx  Case link:

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Show Notes

  1. When building your illness scripts, pay attention to clinical findings that are characteristic for the diagnosis, rather than merely consistent with the diagnosis.
    • Characteristic findings are hallmarks of a particular diagnosis. They are usually present, and when they are, they strongly support the diagnosis; when they are absent, they argue strongly against the diagnosis. I.e. their presence or absence significantly alters the likelihood of a diagnosis.
    • Expert diagnosticians rapidly recognize characteristic findings, based on the clinical context.
  2. Hypothesis driven reasoning often involve both the fast and slow processor. Optimal utilization of the combination is crucial to avoid cognitive biases
  3. An anomalous clinical data is often times the only clue to the incoherence of a hypothesis. Its presence calls for rethinking your diagnosis creatively, don’t ignore it!
  4. Disease processes that involve multiple organ systems may have highly variable clinical presentation. Don’t be fooled by a rigid illness script.


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