Irritable Bowel Syndrome Is Demonstrably Not "All in the Mind”

The irritable bowel syndrome (IBS) is a disorder of the gastrointestinal tract characterized by recurrent abdominal pain and discomfort, accompanied by alterations in bowel function (diarrhea, constipation, or a combination of both).  It’s generally regarded as an exclusively functional disorder, i.e. the affected organ – the lower bowel - functions abnormally, but without any anatomical disorder or demonstrable pathology.  Although IBS patients tend to have anxiety and/or depression - not surprising, in view of their symptoms - they are tired of being told the condition is “all in their mind”.  Now they have support from a study done at the University of California, Los Angeles, and published in the journal Gastroenterology.

Magnetic resonance imaging (MRI) scans were used to compare the brain anatomy of 55 women with moderate IBS and 48 age-matched healthy women.  The researchers found there was thinning of the grey matter - the part of the brain that’s rich in neurons - in specific areas of the brain.  These were areas involved in cognitive and evaluative activity, chiefly in the prefrontal and posterior parietal cortex.  However, brain areas linked to anxiety and depression were no different in IBS patients than in anxious or depressed people without IBS.

The principal investigator summarizes the relevance of these results: "Discovering structural changes in the brain ... demonstrates an 'organic' component to IBS and supports the concept of a brain-gut disorder.  The finding removes the idea once and for all that IBS symptoms are not real and are only psychological.”  Future studies should look at family members of IBS patients, to see if they have inherited the same brain anatomy that may increase a person's risk of IBS. This would indicate a  genetic component of IBS and point the possible way to new treatments (many years hence!).