The invention concerns a barrier ring for attaching an ostomy appliance to a peristomal skin surrounding a stoma, the barrier ring comprising a generally oval shaped body (11) with tapered peripheral end portions (14,16) a convex proximal bodyside surface (18) a flat bottom surface (20) and a stoma-receiving aperture (12) wherein the bodyside surface, when viewed in a cross-section taken along the major axis defines a convex surface transitioning to a concave surface from the stoma-receiving aperture to a respective tapered peripheral end portion.
