A controlled discharge ostomy appliance (10) comprising: a stomal aperture (18)； a non-entrant stoma seal (22)； an inner coupling member (24) coupled to support the stoma seal for retaining the stoma seal in an operative position with respect to the stomal aperture； and an outer coupling member (20) around the inner coupling member for supporting the appliance. The operative position is selected such that, in use, a seal pressure applied between the stoma seal and the stoma when the stoma is quiescent is not more than about 1 psi.
