Fibromyalgia, CFS More Prevalent in Patients With IBS

Marilynn Larkin

November 16, 2023


Irritable bowel syndrome (IBS) is associated with increased odds of fibromyalgia and chronic fatigue syndrome (CFS), new research suggests.


  • The authors conducted a retrospective cohort study to investigate the prevalence and predictors of fibromyalgia and CFS in patients hospitalized with IBS vs people without IBS.

  • The researchers used ICD-10 codes to analyze US National Inpatient Sample (NIS) data from 2016-2019.

  • A subgroup analysis investigated associations with IBS-diarrhea (IBS-D), IBS-constipation (IBS-C), and IBS-mixed types.

  • Variables included patient age, sex, ethnicity, race, household income, insurance status, and hospital-level characteristics (including location, bed size, and teaching status).


  • Among 1.2 million patients with IBS included in the study, 10.7% also had fibromyalgia and 0.4% had CFS. The majority of fibromyalgia (96.5%) and CFS (89.9%) patients were female and White (86.5%). CFS prevalence also was highest among White persons (90.7%).

  • The prevalence of fibromyalgia and CFS was significantly higher in patients with IBS compared to those without IBS (adjusted odds ratio [AOR], 5.33 for fibromyalgia and AOR, 5.4 for CFS).

  • IBS-D, IBS-C, and IBS-mixed types were independently associated with increased odds of fibromyalgia and CFS.

  • Independent predictors of increased odds of fibromyalgia and CFS, respectively, were increasing age (AOR, 1.02 for both), female sex (AOR, 11.2; AOR, 1.86) and White race (AOR, 2.04; AOR, 1.69).

  • Overall, White race, lower socioeconomic status, smoking, alcohol use, obesity, and hyperlipidemia were associated with increased odds of fibromyalgia. For CFS, increased odds were associated with White race, higher socioeconomic status, smoking, obesity, and hyperlipidemia.


"In current clinical practice, there is a high risk of neglecting multi-syndromic patients. We as clinicians should integrate in our practice with regular screening for other somatic disorders in the IBS population and determine the need to consult other specialties like rheumatology and psychiatry to improve the overall health outcome in IBS patients,” the authors write.


Zahid Ijaz Tarar, MD, University of Missouri School of Medicine, Columbia, led the study, which was published online in Biomedicines.


The retrospective design of the study can only show associations, not a causal relationship. Lack of blinding and randomization in the data creates bias. The NIS database does not provide medication and laboratory data, so the effect of pharmaceutical therapies cannot be measured.


The research received no external funding. The authors declare no potential conflict of interest with respect to the research, authorship, and/or publication of this article.

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