An ostomy appliance having first and fourth walls connected to each other at or near their peripheries, the first wall having a stoma-receiving opening； second and third walls positioned in between the first and fourth walls, the second wall being connected to one or more of the first, third and/or fourth walls, and the third wall being connected to one or more of the first, second and/or fourth walls； a waste collecting cavity defined between either the first and second walls or first and fourth walls； a second cavity defined between the second and third walls； a third cavity defined between the third and fourth walls； a first gas flow path in the second wall to permit waste gases to pass from the waste collecting cavity to the second cavity； a second gas flow path in the third wall to permit waste gases to pass from the second cavity to the third cavity； and a third gas flow path in the fourth wall to permit waste gases to escape from the third cavity, wherein the second and third walls are connected to each other so as to define a liquid flow path which permits liquid within the second cavity to flow into the waste collecting cavity.
