The most important thing you can do to keep your skin healthy is to use ostomy supplies that fit well and stay in place. Two Piece Systems are most suitable for colostomies or ileostomies. Two-piece systems allow you to apply a new pouch without removing the skin barrier from your body each time. The skin barrier is separate from the pouch. The pieces snap together with a flange, a part that looks like a plastic ring. It is easy to unsnap the pouch and discard the pouch as often as you like. If you want to change your pouch more frequently than the skin barrier, choose a two-piece system.