A device to block emesis and/or reflux includes a tube insertable into the esophagus. A valve is carried by the tube and includes a flexible sheath having an upper edge secured onto the tube and an unsecured lower circumferential edge and configured such that upon contact with emesis and/or reflux from the stomach, 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.
