According to a recent study published in the January 9th issue of the Journal of Neuroscience, abnormal brainstem function may be responsible for irritable bowel syndrome. The purpose of the study was to seek out abnormal neurological responses for anticipated pain. According to Steven Berman, M.D., of UCLA, when patients with irritable bowel syndrome anticipated abdominal pain that was not dangerous via stimuli they showed increased activity in areas of the brain that dictate sensation of pain and emotional arousal. One of the most important symptoms of irritable bowel syndrome is anxiety about the condition, which can increase sensation of physical symptoms. The following is an excerpt of an article from Medpage Today that reviews the study:
The investigators studied 14 women with irritable bowel syndrome and 12 healthy women. Participants underwent a balloon-driven rectal distention procedure that causes no tissue damage but creates sensations of pressure. The procedure included a light-based visual cue to signal the start. Distentions of 25 and 45 mm Hg were induced, as was a sham distention of 5 mm Hg.
Questionnaires administered just prior to the procedure confirmed that the irritable bowel syndrome patients were more anxious, angry, and stressful beforehand than the healthy individuals. The patients had mean scores of 6.0 for stress, 6.0 for anxiety, and 5.8 for anger at baseline. Corresponding values for controls were 3.2 (P<0.0001), 2.5 (P<0.0001) and 2.4 (P=0.0002).
During the procedure, activity in participants’ insula, amygdala, and brainstem was monitored with functional MRI.