A drainage bag for receiving bodily waste, such as an ostomy bag, comprises an outer bag of material soluble in cold water, e.g. polyvinyl alcohol, and an inner bag of material insoluble in water at ambient temperature and body temperature but soluble in organic solvent, e.g. 2-oxepanone polymer (polycaprolactone). When the bag (and contents) are to be disposed of, appropriate organic solvent (e.g. benzyl alcohol) is applied to the inner bag. The bag can then be placed in a WC bowl and is flushable after about 1-2 minutes.