A prosthetic device is described that is positionable within the gastro-esophageal junction region of a patient. The prosthetic device includes a proximal opening and a distal orifice that is adjustable in size prior to and/or following implantation. During use, the prosthetic device is attached to tissue of the gastro-esophageal junction region of the patient, with the device positioned such that food ingested by the patient passes from the esophagus through the proximal opening into the interior of the prosthetic device, and eventually exits the prosthetic device via the distal opening.