Cannabinoid hyperemesis relieved by compulsive bathing.

Cannabinoid hyperemesis is a clinical syndrome characterized by repeated vomiting and associated learned compulsive hot water bathing behavior due to long-term marijuana use. Research has identified type 1 cannabinoid receptors in the intestinal nerve plexus that have an inhibitory effect on gastrointestinal motility. This inhibitory effect may lead to hyperemesis in marijuana users. The thermoregulatory role of endocannabinoids may be responsible for the patient's need to take hot showers. We report 2 cases of cannabinoid hyperemesis that demonstrate this unusual adverse effect of marijuana use.