Placebo effect in patients with irritable bowel syndrome

The placebo effect has evolved from being considered a nuisance factor in clinical research to a hot topic of scientific investigation. New research findings show that a placebo has real psychobiological and biological effects that are attributable to the overall therapeutic context. Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract that shows a significant placebo response of around 40-50% among different clinical trials. A positive patient-practitioner relationship can enhance the placebo effect in IBS patients. Emerging literature using functional brain imaging has started to document the neuronal changes associated with the placebo phenomenon in IBS patients, showing aberrant neural network during visceral placebo analgesia when compared to controls. Further promotion and integration of laboratory and clinical research are encouraged to advance the understanding of placebo mechanisms in IBS patients.