TUESDAY, July 27, 2010 (HealthDay News) -- Women with irritable bowel syndrome have increases and decreases in gray matter density in areas of the brain that play a role in attention, emotion regulation, pain inhibition and the processing of information from the gut, new research suggests.
Similar brain structural changes have been noted in patients with pain disorders such as lower back pain, migraines and hip pain.
Irritable bowel syndrome, or IBS -- which can cause pain and discomfort in the abdomen, along with constipation, diarrhea, or both -- affects about 15 percent of the U.S. population, mainly women. Among those in the medical field, IBS is currently considered a "functional" syndrome (the digestive tract is not working properly), rather than an "organic" disorder (which would involve structural organ changes).
"Discovering structural changes in the brain, whether they are primary or secondary to gastrointestinal symptoms, demonstrates an 'organic' component to IBS and supports the concept of a brain-gut disorder," study author Dr. Emeran Mayer, a professor of medicine, physiology, and psychiatry at the David Geffen School of Medicine, University of California, Los Angeles, said in a university news release.
"Also, 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 added.
In the study, American and Canadian researchers used medical imaging to analyze anatomical differences in the brains of 55 female IBS patients and 48 women without IBS. The IBS patients had increases and decreases of gray matter in specific cortical brain regions involved in cognitive and evaluative functions, the investigators found.
"We noticed that the structural brain changes varied between patients who characterized their symptoms primarily as pain, rather than non-painful discomfort. In contrast, the length of time a patient has had IBS was not related to these structural brain changes," Mayer said.
The study is published in the July issue of the journal Gastroenterology.
The next steps in this research will include trying to determine if certain genes are related to the structural brain changes in IBS patients.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about IBS.