Abstract: A barrel serves as a reservoir in which a treatment fluid is to be contained and within which barrel is a slideable plunger. A connector at one end of the barrel is receptive to attachment of a cannula. Another connector is located at the other end of the barrel. A housing has a coupling attachable to that other connector. On the housing is a detachable fitting receptive of a hose which delivers air under pressure. Included in the housing is an adjustable air pressure regulator in an air flow path between the detachable fitting and the coupling with the regulator being selectively adjustable to control the flow of the air in that path. Associated with the irrigator is a container for the treatment fluid and which includes a pump sealingly attachable to the one end of the barrel for delivering the fluid into the reservoir in response to movement of the barrel.