An ostomy appliance (101) comprising a pouch and a filter construction (110) is provided. The filter construction has a first and second foil layer (111, 112) to provide an enclosure for the elements in the filter construction. The filter construction is attached inside the pouch so that the filter construction is free-hanging inside the pouch. The two foil layers may be generally parallel with the walls of the ostomy bag. The foil layers are provided with numerous holes functioning as gas-inlets (114) for the filter construction. The filter construction includes a prefilter element (115) and a deodorising filter (117). When the ostomy appliance is used for collecting discharge, the number of balloonings can be reduced and the time to ballooning can be increased.
