A drainable ostomy appliance including: first and second walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening; a collecting cavity defined between the first and second walls; a connection member connected to the first wall for attaching the appliance to a user or for attaching the appliance to a flange for attaching the appliance to a user; an outlet which extends away from the stoma-receiving opening, the outlet terminating at an opening; a first stiffening member positioned at or near the opening and extending across the outlet, the first stiffening member having an edge portion which is positioned close to the opening of the outlet; a second stiffening member positioned at or near the opening and extending across the outlet, the second stiffening member having an edge portion which is positioned close to the opening of the outlet; wherein the edge portions abut or are positioned next to each other when the opening is closed and wherein the edge portions form a continuous curved profile.