Abstract: An ostomy bg of a wc disposable material has a multi-layer wall with an opening that is secured in register with the patient's stoma by means of a flange. The flange comprises an internal ring and an external ring secured together around the opening. The internal ring has an adhesive front surface secured to the inner surface of the wall around and overlapping the opening. The external ring is of an adhesive material with a backing sheet on its rear side which prevents the external ring adhering to the front of the wall. The external ring overlaps the opening and is exposed by the backing sheet within the opening so that it adheres to the internal ring and protects the edge of the bag opening from body waste material.