The invention provides an ostomy bag assembly including an outer bag and an inner bag secured to one side of a flange. The inner bag is removable to facilitate disposal. The flange has a polymeric backing film and a layer of bioadhesive for securing the ostomy bag assembly to the body of a patient. The flange includes an orifice to enable bodily waste to be received by the inner bag. The outer bag is detachably bonded to a first attachment zone on the flange and the inner bag is secured to a second attachment zone on the flange. The outer bag is mounted to the flange by an annular bonding element is formed from a multilayer polymeric material comprising first and second ethylene vinyl acetate layers and a polymeric support layer interposed there between. A method of fabricating ostomy bags is also provided.