By Emma Lindqvist, Clinical Education Manager, Stoma Care ยท Category: Clinical Practice ยท Published 20 May 2026
Ask someone with a stoma what they worry about and leaks will be at or near the top of the list. Ask them what a leak actually costs them and the answer is rarely about laundry. It is about the meeting they left early, the swim they did not take, the night they lay awake checking. Leakage is a clinical problem with an emotional invoice.
Leaks are a fit problem, not a discipline problem
The most damaging assumption in stoma care is that leaks happen because someone has not learned to apply their appliance properly. In the overwhelming majority of cases the technique is fine. The fit is not.
A flat baseplate is designed for a flat, firm, predictable abdomen. Very few abdomens are any of those things, and almost none of them stay the same shape when the person sits, bends, coughs or breathes out. The gap between a rigid product and a moving body is where output escapes.
Body factors that defeat a flat baseplate
- A stoma that is flush with the skin, retracted, or sits below the surface when seated.
- Soft, yielding abdominal tissue that dips away around the stoma base.
- Skin creases, folds or scar lines radiating from the stoma.
- A parastomal hernia or an uneven bulge that changes with posture.
- Significant weight change since the appliance was first fitted.
- A stoma sited close to the waistline, a scar or the iliac crest.
What convexity actually does
Convexity describes a baseplate whose skin-facing surface curves outward. That curve does two things at once. It applies gentle pressure to the peristomal area, which pushes down the surrounding tissue, and in doing so it encourages the stoma to protrude slightly further, so output is delivered into the pouch rather than tracking sideways under the adhesive.
Historically, convexity meant firm convexity: effective, but rigid, and capable of causing pressure damage or ulceration on fragile skin if the depth was wrong. It was often treated as a last resort after several failures.
Soft convexity: adapting to the body rather than overruling it
Soft convexity uses a more flexible, lower-tension curve that deforms with the abdomen instead of imposing a fixed shape on it. The practical differences matter.
- It moves with the patient. The baseplate flexes as the person sits, twists or bends, so the seal is maintained through posture change rather than only when standing still.
- It distributes pressure. A gentler, broader force reduces the risk of the pressure-related skin damage sometimes associated with deep, rigid convexity.
- It suits fragile and sensitive skin. That opens convexity to patients who would previously have been excluded from it.
- It can be used earlier. Because the risk profile is lower, soft convexity does not have to be a rescue product deployed after weeks of sore skin.
This thinking sits behind Esteem Bodyโข with Leak Defenceโข, which pairs an adaptive soft convex profile with a skin barrier designed to hold its seal as the body moves. It is complemented by eakin cohesiveยฎ seals and Stomahesiveยฎ, which fill dips and creases so the baseplate meets an even surface.
A practical assessment sequence
- Assess seated, not supine. Ask the patient to sit, then bend forward. Most of the topography that causes leaks only appears in these positions.
- Feel the peristomal plane. Run a finger around the stoma base and map any dips, folds or softness within the baseplate footprint.
- Measure again. Stoma size changes after surgery, with weight change and over time. An out-of-date template is a common and easily fixed cause of leakage.
- Read the leak pattern. Where output escapes on the baseplate tells you which part of the seal is failing and in which posture.
- Match the depth. Shallow soft convexity for gentle dips and flush stomas; deeper profiles for genuine retraction. More is not better.
- Add accessories deliberately. A seal or ring should fill a defined defect, not compensate for the wrong baseplate.
- Review inside two weeks. Confidence is rebuilt by a change that demonstrably works, and quickly.
Why this matters beyond the skin
Every prevented leak protects peristomal skin integrity, reduces unscheduled appointments and lowers product wastage from premature changes. It also gives someone back the thing they lost first, which was the freedom to stop thinking about it.
Convatec Academy provides body-profiling training and product selector tools for stoma care teams. me+โข supports patients with fitting guidance and samples.