Abstract

Irritable bowel syndrome (IBS) is a heterogeneous and complex functional gastrointestinal disorder with a
global prevalence of approximately 11% and high geographic variation. IBS encompasses various symptom
clusters considered to reflect complex patho-etiological mechanisms, and effective treatment options are
limited, with most medications targeting individual mechanisms and symptoms. Therefore, multi-targeted
treatment is required. IBS is currently viewed as a disorder of disturbed gut–brain interactions with
abnormalities at different sites along the gut–brain axis, including altered gastrointestinal motility, visceral
hypersensitivity, increased intestinal permeability, and altered gut microbiota. All of these abnormalities
represent individual targets for STW 5, a herbal preparation with nine different extracts indicated for the
treatment of functional dyspepsia and IBS. As a multi-targeted medicinal drug, STW 5 possesses multiple
pharmacodynamic effects. Several in vitro and in vivo studies have demonstrated STW 5 efficacy on numerous
IBS patho-mechanisms targeting gastrointestinal smooth muscles, visceral afferent nerves, inflammation, gut
permeability, and the gut microbiome.

Keywords

irritable bowel syndrome, hypersensitivity, visceral motility, inflammation, microbiome, STW 5, herbal medicine