Centrally mediated disorders of gastrointestinal pain

Centrally mediated abdominal pain syndrome, formerly known as functional abdominal pain syndrome, can be distinguished from other functional gastrointestinal disorders by its strong central component and relative independence from motility disturbances. Centrally mediated abdominal pain syndrome is a result of central sensitization with disinhibition of pain signals rather than increased peripheral afferent excitability. A newly described condition, narcotic bowel syndrome/opioid-induced gastrointestinal hyperalgesia, is characterized by the paradoxical development of, or increases in, abdominal pain associated with continuous or increasing dosages of opioids. Patients only have relief when opioids are withdrawn. We define both conditions in the context of epidemiology, pathophysiology, clinical evaluation, and treatment, emphasizing the importance of a physician-patient relationship in all aspects of care.