A naso/orogastric device having backflow blocking means and comprises a naso/orogastric tube sized and shaped for being disposed within the esophagus so that at least a distal end thereof being placed in the stomach lumen of a patient, at least one elastic esophageal body, positioned along the naso/orogastric tube, having a pressure dependent volume, at least one esophageal sensor that detects fluid around at least one segment of the naso/orogastric tube, and a pressure regulator that regulates a pressure within the elastic esophageal body according to the detection.