An anti-reflux catheter includes a central support body having an inner longitudinal passage chamber； a cannula extending out of one end of the central body and connected to the inner chamber； a transverse opening which extends through the central body and communicates with the inner chamber； an outwardly extending mouthpiece of the transverse opening； a flexible sleeve longitudinally accommodated in the inner chamber at the transverse opening and having an outer surface facing such transverse opening, the mouthpiece having a pressure system associated therewith, which act upon the sleeve and is movable between an idle position or an operating pressed position, and vice versa.
