Abstract: A method for accurately and conveniently implanting a selected quantity of a liquid into the colon. The apparatus comprises a positive displacement, plunger type, syringe for holding and dispensing a selected quantity of liquid, a tubular connecter at the outlet end of the syringe, a valve connected to the bore of the connector for selectively connecting the bore to the atmosphere and a tube attached to the tubular connector. A nozzle may be used to attach the tubular connector to a plastic tube which is in turn attached to a rectal catheter. In use, a selected quantity of liquid is drawn into the syringe, the tube is connected thereto, the catheter is inserted well into the colon and the syringe plunger is pressed to dispense the liquid into the tube. Since the tube is then still filled with liquid, the valve is opened and the atmosphere is connected to the tube. In some cases the remaining liquid will drain into the colon by gravity.