 Dronabinol, a cannabinoid receptor agonist with a preference for CB1 over CB2, is believed to reduce the esophageal hypersensitivity. CB1 receptors are located primarily on central and peripheral neurons including the enteric nervous system and myenteric plexus where they modulate neurotransmitter release. Activation of pre-junctional CB1 receptors may reduce excitatory enteric transmission and conceivably improve esophageal hyperreactivity and hypersensitivity, the hallmarks of FCP. 