Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
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    Chief Complaint


    Organ System


    Patent Pending

    Kruis Score for Diagnosis of Irritable Bowel Syndrome (IBS)

    Determines presence of IBS using clinically significant weighted criteria.
    When to Use
    Why Use
    • Patients with highly suspected IBS as a possible confirmatory test.
    • Patients with equivocal symptoms but with an initial negative workup to suggest if further workup should be pursued prior to diagnosing IBS.
    • The Kruis Score helps to different IBS from organic bowel disease.
    • It uses symptoms and lab testing to suggest which patients likely have IBS (high specificity).
    • It is intentionally not a highly “sensitive” test, since IBS is often a diagnosis of exclusion.

    Points to keep in mind:

    As IBS is often a diagnosis of exclusion, often it is appropriate to begin with route lab and/or imaging testing in patients where clinicians have some possible suspicion of organic ideas.

    The Kruis Score can help objectify and validate clinician suspicion of a patient with IBS.

    Red Flags


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    Next Steps
    Creator Insights


    • If IBS is confirmed, a trial of IBS-related medications (antispasmodics, fiber) may be appropriate.
    • If IBS is not confirmed, further evaluation may be indicated, like CT or ultrasound imaging, HIDA scan, endoscopy, or further blood testing.


    Addition of assigned points.

    Facts & Figures

    • If score < 44, negative for IBS.
    • If score >44, positive for IBS.
    • If any “red flags” present, consider further assessment for other pathology.
    Dr. Wolfgang Kruis

    About the Creator

    Wolfgang Kruis, MD, is a practicing internist and professor of medicine at the Clinic for Gastroenterology, Pulmonology and General Internal Medicine at the Evangelical Hospital Kalk in Cologne, Germany. He has published more than 210 original articles in multiple international journals and has contributed to over 20 German textbooks for internal medicine and gastroenterology.

    To view Dr. Wolfgang Kruis's publications, visit PubMed

    About the Creator
    Dr. Wolfgang Kruis