The ornamental design for an ostomyundergarment, as shown and described.
FIG. 1 is a perspective view of an ostomy undergarment showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposite side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view of the ostomy undergarment with security flaps having hook-and-loop fasteners in a detached configuration; and,
FIG. 9 is a front view of the ostomy undergarment with the security flaps having the hook-and-loop fasteners in a detached configuration.
The broken lines in FIG. 1 depict environmental structures of the ostomy undergarment for illustrative purposes only and form no part of the claimed design.