Abstract: At a fixing device for a stomy bag a counter-holding ring (2) is intended to be operated under a patient's outer skin (3) when the intestine (4) is sewed on. A tubular body (1), one end of which is provided with a flange (5) and to which the stomy bag (18) is intended to be connected and whose outer diameter will permit the body (1) to be moved through the counter-holding ring (2) with the flange (5) until contact with the outer skin (3), is provided with an outer peripheral portion (6) of an elastically ductile material and an annular cavity (7) arranged inside this and associated with the outside of the body (1) via a first channel (8).