A method and apparatus for alerting a colostomate or medical attendant to the presence of fecal matter. The device includes a hollow plug detachably securable to a flexible port positioned about the stoma. The port carries an alarm circuit which is triggered when fecal matter enters the plug lumen which will alert the colostomate to an impending episode. The signal may be vibratory, audible or visible and may be transmitted to a remote location. The device includes an inflatable air cuff which, when inflated, presents a physical barrier to the passage of fecal matter. Gas may pass through filters in the tube. The method involves positioning the device in the stoma, inflating the cuff and generating an alarm when matter is sensed.