All in my head or all in my gut? An update on irritable bowel syndrome

Irritable bowel syndrome (IBS) has a considerable impact on patients and healthcare systems. IBS is a disorder of brain-gut interaction with numerous biopsychosocial factors involved, including early life experiences, previous gastrointestinal infections, and coexisting mood disorders. An understanding of the role of the gut-brain axis in symptom generation is vital to enable delivery of holistic care.

We explore psychological mechanisms, such as coexisting anxiety and depression, adverse life experiences, and somatisation and how these impact symptom severity. There is evidence for psychological therapies, such as cognitive behavioural therapy or gut-directed hypnotherapy, in IBS. We go on to summarise gut-based mechanisms, such as abnormal motility, visceral hypersensitivity, inflammation, and dysbiosis. Efficacious treatments targeting these include antidiarrhoeals, laxatives, antispasmodics, drugs acting on ion channels or serotonin, gut-brain neuromodulators, and treatments targeting the microbiota or inflammation. Finally, we consider emerging evidence from models describing distinct IBS phenotypes and their potential to facilitate a more integrated approach to identify best treatment options.

For many patients with IBS, both brain and gut mechanisms must be considered within the context of the biopsychosocial model to enable effective delivery of holistic and personalised care.