In Search of Mechanisms of Change in Treatment Outcome Research: Mediators and Moderators of Psychological and Pharmacological Treatments for Irritable Bowel Syndrome

Targets within the brain–gut axis for the treatment of FGIs. Shown are general target areas for various therapeutic approaches to IBS symptoms. Whereas neurologically directed pharmacologic therapies aim for targets within the spinal cord, brain stem, and limbic and paralimbic regions, psychological therapies are likely to affect thoughts, belief systems, and memories processed in the prefrontal cortex. Through this effect, they may strengthen the cortico–limbic–pontine pain inhibition system and counteract central pain amplification. Modified from Mayer et al.²