If the edges of the barrier begin to detach from your skin, they can lift and create channels underneath. Edges typically lift or roll for a variety of reasons: they may catch on clothing or swell from absorbing lots of moisture after a hot bath or time in a hot tub. Perhaps you didn't seal the edges well to your skin upon application. Or, in some cases, the barrier may not be big enough to follow the movements or stretching of the area around the stoma. Regardless, it's important to ensure the barrier is secure - so that lifting at the edges doesn't compromise the seal around the stoma.