A device designed to help improve contact between the flange of a two-piece or multiple-piece ostomy appliance and the peristomal skin of a flush stoma or more typically a recessed stoma (a stoma with an adjacent depression, scar, crease, or other condition) for which additional barrier-to-skin contact is desirable. The device is placed between the ostomy appliance flange and the stomal skin typically to fill gaps between the two by providing convexity (an outward bulge), reducing the likelihood of leakage. After application, this device cannot be reused.