An ostomy appliance comprising: a ring member (10, 110) having an interior surface and an engagement portion encircling a centrally-located input opening, wherein the engagement portion comprises a plurality of spaced-apart flexible tabs extending radially inward into the input opening, the flexible tabs having opposing side edges and opposing interior and exterior surfaces (26, 28) with an opening extending therebetween, the opening being centrally located between the opposing side edges, a plurality of spaced-apart teeth extending radially inward from the inside surface of the ring member into the input opening, the teeth being in alignment in a first direction with spaces between the plurality of flexible tabs and having an inside surface facing the interior surface of the plurality of flexible tabs; and a rib member having a curved body portion with opposing inside and outside surfaces (42, 44) joined together by opposing top and bottom edges (46, 48) and opposing side edges, the rib member having a dowel, pins and a notched section in the body portion, the dowel extending radially inward from the inside surface of the body portion, the pins extending axially away from the top edge of the body portion, the notched section forming a recess along the inside surface and bottom edge of the body portion, wherein the rib member is removably securable to the ring member whereby the pins of the rib member are insertable into openings of adjacent flexible tabs of the plurality of flexible tabs and a first tooth of the plurality of spaced-apart teeth in alignment in the first direction with a space between the adjacent flexible tabs and is received within the notched section of the rib member, the notched section being seated on the inside surface of the tooth. a ring member (10, 110) having an interior surface and an engagement portion encircling a centrally-located input opening, wherein the engagement portion comprises a plurality of spaced-apart flexible tabs extending radially inward into the input opening, the flexible tabs having opposing side edges and opposing interior and exterior surfaces (26, 28) with an opening extending therebetween, the opening being centrally located between the opposing side edges, a plurality of spaced-apart teeth extending radially inward from the inside surface of the ring member into the input opening, the teeth being in alignment in a first direction with spaces between the plurality of flexible tabs and having an inside surface facing the interior surface of the plurality of flexible tabs; and a rib member having a curved body portion with opposing inside and outside surfaces (42, 44) joined together by opposing top and bottom edges (46, 48) and opposing side edges, the rib member having a dowel, pins and a notched section in the body portion, the dowel extending radially inward from the inside surface of the body portion, the pins extending axially away from the top edge of the body portion, the notched section forming a recess along the inside surface and bottom edge of the body portion, wherein the rib member is removably securable to the ring member whereby the pins of the rib member are insertable into openings of adjacent flexible tabs of the plurality of flexible tabs and a first tooth of the plurality of spaced-apart teeth in alignment in the first direction with a space between the adjacent flexible tabs and is received within the notched section of the rib member, the notched section being seated on the inside surface of the tooth.