An indicator assembly for use with a non-vascular catheter device. The indicator assembly includes: a first retainer secured to a catheter tube, the first retainer being an indwelling retainer which is deployed within a non-vascular lumen or cavity of the body; a second retainer secured to the catheter tube, the second retainer deployed outside the human body; and an indicator located outside the body on the catheter tube between the first retainer and the second retainer. The first retainer and the second retainer are configured to maintain substantially the same position with respect to each other on the tube and the indicator is configured to signal a change in position with respect to either the first or the second retainer, thereby indicating a change in the length of a stoma.