Faulty Narrative with Functional Nausea Study

A recent study (SE Tarbell et al J Pediatr 2020 225: 109-108. Children with Functional Nausea—Comorbidities outside the Gastrointestinal Tract) highlights the frequent comorbidities in children with functional nausea. The authors have combined prospective and retrospective elements with specific questionnaires and review of the electronic medical records.

Key points:

  • High rates of comorbidities were noted: Abdominal pain 94%, Headache 83%, Orthostatic Intolerance 81%, Fatigue 75%, Disturbed sleep 71%, Anxiety 59%, and Constipation 57%. Other frequent findings included vomiting in 51%, Allergies 54%, , Joint Pain 46%, Hypermobility in 37%.
  • 69.5% of subjects missed more than 10 days of school due to their symptoms.
  • There was extensive testing in this cohort (n=63), including 96 endoscopies, and 199 radiologic tests. In addition, 4 patients had cholecystectomies.
  • Among 64 EGDs, 28 were considered abnormal. The authors claim that 6 had specific findings: H pylori (n=2), polyps (n=2), celiac disease (n=1), and lactase deficiency (n=1).
    • It is likely that H pylori and celiac disease could have been identified/suspected by non-invasive testing; these two findings may make a diagnosis of functional nausea more tricky.
    • Lactase deficiency could be considered a normal finding.
  • The authors state that 32 of 59 AXRs had “moderate to severe constipation” based on stool burden

Overall, this article makes some useful points about the high rate of comorbidities with functional nausea but I disagree with some of the other discussion points.

The authors claim that “negative tests can reassure families of the absence of a more serious underlying condition.” This assertion has been disputed in other studies. In one study (A Rolfe et al. JAMA Intern Med. 2013;173(6):407-416 Full text: Reassurance After Diagnostic Testing With a Low Pretest Probability of Serious Disease), the authors conclude that ‘diagnostic tests for symptoms with a low risk of serious illness do little to reassure patients, decrease their anxiety, or resolve their symptoms, although the tests may reduce further primary care visits.’

The authors also have a permissive attitude regarding AXRs saying “a radiograph may validate a diagnosis of constipation.” Yet the preponderance of evidence indicates that AXRs are not needed or recommended for the diagnosis of constipation. The juxtaposition of this statement on page 107 of this issue with the next article on page 109 which details a quality improvement process of reducing abdominal radiographs to diagnose constipation in the ED is interesting. The ED physicians in the next article are trying to adhere to evidence-based guidelines; in this article, the authors correctly note that evidence “has shown abdominal radiographs to be unreliable in establishing an association between clinical symptoms of constipation and fecal load on abdominal radiographs.”

My take: Tarbell et al show that in patients with functional nausea, nausea is the tip of the symptom iceberg. Generally, radiographic and endoscopic diagnostic studies have very low yield and should be discouraged.

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2 thoughts on “Faulty Narrative with Functional Nausea Study

  1. I’m curious about the reassurance concept…..the JAMA study, that I believe you have mentioned in the past as well, is an adult population. I wonder if there is well established data (more than a single study) for the pediatric population, where the decision maker and the one that needs reassurance often is not the patient.

    AXRs for the diagnosis of constipation should be a forbidden sin, but I think we owe our non-GI colleagues some leeway. The AXR may often be done to rule out some more ominous problem rather than diagnose constipation. Radiologists should also be conservative on stating “constipation” in their interpretation.

    Regarding the number of positive findings on EGD, over 30% seems like a higher percentage than many other tests we do sometimes, like “routine blood work.” Also, I believe our own H. pylori guidelines actually encourage endoscopic assessment with an added goal of culturing organism to tailor abx use.

    While Celiac serology is vastly improved and newer and future guidelines will support less endoscopic assessment, there are still many clinical scenarios that encourage biopsy proof, particularly when clinical picture is not clear cut (i.e. functional nausea) or serology is not overwhelmingly abnormal.

    • All good points. The comments about celiac and H pylori are mainly due to the idea that EGD had a higher yield in this study of ‘functional nausea’ than others and could have been suspected based on noninvasive workup.

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