An ostomy appliance is necessary when surgery creates an opening (stoma) on the abdomen to reroute the intestine or urinary tract. This requires a collection system, and the adhesive component securing it to the skin is crucial. However, inconsistent terminology used by manufacturers and healthcare providers often confuses users. This variation requires patients to learn multiple terms for the same item, complicating supply ordering and care discussions.
The Core Terminology: What It’s Called
The adhesive component that adheres directly to the skin around the stoma is most accurately referred to as the Skin Barrier. This name reflects its primary function: protecting the delicate peristomal skin from the stoma’s corrosive output. Despite this clear functional name, it is frequently called by several other names, often depending on the manufacturer or regional preference.
Another widely recognized term is the Wafer, which describes the thin, flat, disc-like shape of the adhesive material. Similarly, the term Baseplate is used, particularly to emphasize that this piece forms the secure, foundational layer upon which the collection pouch is ultimately attached. These three terms—Skin Barrier, Wafer, and Baseplate—are generally interchangeable and refer to the same adhesive patch that covers the skin.
The term Flange is also common, but its meaning is often more specific. While some use “flange” synonymously with wafer or skin barrier, it usually describes the coupling ring mechanism in a two-piece system. This mechanism allows the pouch to snap or lock onto the adhesive barrier. For most purposes, however, all these names point to the same adhesive product contacting the skin.
Understanding One-Piece and Two-Piece Systems
The collection apparatus is categorized into two structural formats: one-piece and two-piece systems. A one-piece system permanently fuses the skin barrier and the collection pouch into a single unit. When the appliance needs changing, the entire unit is removed from the skin and replaced.
In contrast, the two-piece system consists of the skin barrier and the pouch as two distinct components. They attach via a coupling system, such as a mechanical ring or an adhesive surface. This separation allows the user to change the pouch without peeling the barrier off the skin, promoting better skin health by reducing irritation from frequent removals.
The two-piece design is considered more versatile because it permits the barrier to remain in place for a longer period, often several days, while the pouch is changed as needed. The one-piece system is praised for its simplicity and lower profile, as it lies flatter against the body. Both systems utilize the same adhesive barrier material.
Function and Composition for Skin Protection
The primary purpose of the adhesive barrier is to create a secure, leak-proof seal around the stoma. This prevents effluent from contacting the surrounding skin. Stoma output contains digestive enzymes or corrosive waste that can quickly cause skin breakdown, making this protection important. The barrier must remain securely adhered for an extended period, often three to seven days, depending on the type and user’s output.
The composition of these barriers makes them uniquely suited for this wet, sensitive environment. The adhesive material is primarily a hydrocolloid, a substance that is both adhesive and absorbent. Key ingredients include natural fluid-absorbing polymers such as pectin, gelatin, and sodium carboxymethylcellulose (CMC). These materials are dispersed within a pressure-sensitive adhesive matrix, often made of elastomers like polyisobutylene.
When the hydrocolloid contacts moisture, such as perspiration or small amounts of stoma output, it absorbs the fluid and forms a protective gel. This controlled swelling action helps maintain the seal and protect the skin. It also allows the barrier to be gentle enough to avoid damaging the skin upon removal. Different hydrocolloid formulations dictate whether a barrier is standard wear or extended wear, with the latter resisting liquid breakdown for a longer duration.
Variations in Barrier Design
Beyond the core material, barriers come in different physical profiles to accommodate the unique anatomical needs of each user. The two main profiles are flat and convex, which refer to the shape of the adhesive surface that contacts the skin. A flat barrier is a level disc that works best for stomas that naturally protrude well above the skin surface and for users whose skin surface around the stoma is flat and even.
A convex barrier features a gentle, curved or dome shape that protrudes outward toward the skin. This design is used when the stoma is flush with the skin, recessed, or if there are folds and creases in the abdominal surface. The convexity applies gentle, focused pressure on the skin immediately surrounding the stoma. This pressure encourages the stoma to protrude slightly, flattens skin irregularities, and directs output away from the skin, improving the seal and preventing leakage.
Users also choose between pre-cut and cut-to-fit barriers, which relates to the opening size for the stoma. Pre-cut barriers have a manufactured opening, suitable for a stoma whose size and shape have stabilized. Cut-to-fit barriers require the user to cut the center opening to the stoma’s exact size and shape. This customized fit is beneficial for new ostomates whose stoma is still changing size or for stomas with an irregular shape.