A device blocks emesis and/or reflex and includes a tube insertable into the esophagus. The tube includes an inflation lumen. A valve is carried by the tube and includes a flexible sheath having an upper edge secured onto the tube and a lower circumferential edge. An inflatable balloon is associated with the flexible sheath and in communication with the inflation lumen. Upon inflation of the balloon, the flexible sheath opens in a concave configuration towards the stomach and the unsecured lower circumferential edge engages the esophageal wall and blocks emesis and/or reflux from the stomach passing into the esophagus past the valve.