Narcotic bowel syndrome and opioid-induced constipation.

Prescription opioid use for chronic non-cancer pain has reached epidemic levels in the USA. With this increased use is the recognition of serious opioid-related gastrointestinal complications such as narcotic bowel syndrome (NBS) and opioid-induced constipation (OIC). NBS consists of a paradoxical worsening of abdominal pain with escalating doses of opioids and is likely mediated by the central nervous system. Therapy requires an intensive multidisciplinary approach to detoxification. OIC is the most common gastrointestinal side effect of opioids. Several novel therapeutics are available to treat OIC that fails to respond to laxative therapy. This review will summarize recent findings on the pathophysiology and treatment approaches to NBS and OIC with a focus on controversies about diagnosis and intervention.