The present invention relating to an improved colostomy device is for preventing the external and internal balloons from being pushed into the upper part of the rectum as well as preventing the leakage of liquids and gases with its perfect air-tight feature and for helping insert the colostomy device to the patients. To achieve the above object, when composing a colostomy device with internal and external balloons (4) and (6), and drainage hose (8), a fixing aid is disposed on the external side of the drainage hose (8) and the front end sides of the rim of the supporting tube (15) is wrapped by a protection membrane (19) between the internal and external balloons.