Overlap between functional GI disorders and other functional syndromes: what are the underlying mechanisms?

Authors

  • S. E. Kim,

    1. Oppenheimer Family Center of Neurobiology of Stress, Los Angeles, CA, USA
    2. Department of Medicine, Greater Los Angeles Veterans Administration Medical Center, Los Angeles, CA, USA
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  • L. Chang

    1. Oppenheimer Family Center of Neurobiology of Stress, Los Angeles, CA, USA
    2. Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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  • Correction added after online publication 21 August 2012: Copyright line for the reuse of Figures 1 and 2 modified from “Permission obtained from Functional Somatic Syndromes, Eds: EA Mayer and C Bushnell” to “Adapted from229. This figure has been reproduced with permission of the International Association for the Study of Pain® (IASP®). The figure may not be reproduced for any other purpose without permission.”

Address for Correspondence
Lin Chang, M.D., Oppenheimer Family Center for Neurobiology of Stress, David Geffen School of Medicine at UCLA, 10833 LeConte Avenue, CHS 42-210 Los Angeles, CA 90095-7378, USA.
Tel: +31 0206 0192; fax: +31 0825 1919; e-mail: linchang@ucla.edu

Abstract

Abstract  Background  Irritable bowel syndrome and other gastrointestinal (GI) and non-GI disorders such as functional dyspepsia, fibromyalgia, temporomandibular joint disorder, interstitial cystitis/painful bladder syndrome, and chronic fatigue syndrome are known as functional pain syndromes. They commonly coexist within the same individual. The pathophysiologic mechanisms of these disorders are not well understood, but it has been hypothesized that they share a common pathogenesis.

Purpose  The objective of this review is to discuss the proposed pathophysiologic mechanisms, which have been similarly studied in these conditions. These mechanisms include enhanced pain perception, altered regional brain activation, infectious etiologies, dysregulations in immune and neuroendocrine function, and genetic susceptibility. Studies suggest that these functional disorders are multifactorial, but factors which increase the vulnerability of developing these conditions are shared.

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