The present invention relates to a medical device for changing the shape of hollow organs in the human body, comprising at least one issue clamp, clip or anchor, which can be fixed to the organ tissue by means of a clamping or hooking-in action in order to provide a fixation point or a point of transmission of force in the organ. The clip or anchor has a receiving-element portion or hooking-in device for a flexible band, wire or tube, by means of which a force causing the change in shape can be applied to the organ at least partially via the clip.