An ostomy pouch (10) and high-performance gas filter assembly (20) therefor, inwhich the filter assembly includes an envelope (21) defining a filter chamber (24)containing a radial flow deodorizing filter pad (26). The pad's opposite faces(26a, 26b) are joined to the inner surfaces of the envelope in such way that theperiphery of the pad is fully exposed within the chamber. A first passage (29) extendsthrough the filter and communicates with a first opening (34) in a wall of the envelopeover which a first microporous membrane (35) extends. A second opening (37) extendsthrough the opposite wall of the envelope at a distance spaced laterally fromthe first opening, and a second hydrophobic microporous membrane (38) extendsover the second opening. In a preferred embodiment, the filter pad is oblong inshape and has a second passage (140) spaced laterally from the first passage (129)and communicating with the second aperture.
