From Our 2010 Archives
Irritable Bowel Syndrome in the Brain
IBS Patients' Brains on High Alert, With Less Control of Emotion and Pain
Daniel J. DeNoon
Reviewed By Laura J. Martin, MD
July 23, 2010 -- Irritable bowel syndrome (IBS) may be in the brain, not in the mind.
Now there's evidence that their underlying problem may be due to the structure of their brains, says Emeran Mayer, MD, professor of medicine, physiology, and psychiatry at the University of California, Los Angeles.
"Discovering structural changes in the brain ... demonstrates an 'organic' component to IBS and supports the concept of a brain-gut disorder," Mayer says in a news release. "The finding removes the idea once and for all that IBS symptoms are not real and are 'only psychological.' The findings will give us more insight into better understanding IBS."
Mayer, David A. Seminowicz, PhD, and colleagues at UCLA and Canada's McGill University used sophisticated scans to compare the brain anatomy of 55 women with moderate IBS to 48 age-matched healthy women.
The finding: Thinning grey matter -- the part of the brain rich in neurons -- in specific areas of the brain. The affected areas involve:
Importantly, brain areas linked to anxiety and depression were no different in IBS patients than in anxious or depressed people without IBS.
The findings, Seminowicz and colleagues suggest, point to a difference between IBS and chronic pain syndromes such as fibromyalgia.
In chronic pain syndromes, nerves constantly send increased pain signals to the brain. But in IBS, the brain itself seems to be amplifying pain signals it receives from the bowel.
The researchers say future studies should look at family members of IBS patients, to see if they inherited the same brain anatomy that may increase a person's risk of IBS. If so, the studies may reveal genetic components of IBS and point the way to new treatments.
The study appears in the July issue of the journal Gastroenterology.
SOURCES: Seminowicz, D. Gastroenterology, July 2010; manuscript received ahead of print.