A controlled discharge ostomy appliance assembly comprises (i) a stoma seal that is self-urging with a dynamic damping characteristic that resists changes of seal volume, (ii) a press-fit coupling member displaceable from an unlocked position to a locked position as part of a press-fit process, and (iii) a single-use frangible portion. The assembly further includes a protector shield removably fastened to the appliance forming a combined assembly therewith. The protector shield comprises (i) a seal displacer manipulable for displacing the stoma seal to a non-operative position ready for fitting, (ii) a substantially rigid coupling member guard portion for protecting the state of the coupling member, and (iii) a bracing portion for bracing the single-use frangible portion.