This topic is about understanding why someone with a parastomal hernia might consider using a convex ostomy appliance. A new ostomate, who is just a couple of months post-surgery, has noticed a small bulge under their stoma, similar to half an orange. They are curious about the advice to switch to a convex pouching system, as it seems counterintuitive to them. Here are some insights and advice on this matter:

1. What convex wafers actually do:
- Convex wafers are designed with a slight bowl shape. This shape allows the outer edge to press gently into the skin, helping to flatten the area and hold the stoma out into the pouch. This can create a firmer seal, which is particularly useful if the stoma is at or below skin level.

2. Not all convex systems look or act the same:
- Some products, like the Coloplast “Flip” pouch, have a base that bulges outward. However, many other convex products have only a slight rise around the stoma opening. Trying different brands or models might help find a better fit.

3. When convex makes sense vs. when a flat wafer is fine:
- If the stoma protrudes well and there are no leaks, a flat one-piece appliance can work even with a hernia. The saying goes, “if it isn’t leaking, don’t change it.”
- Convexity is most beneficial when the stoma is flush, retracted, or if leaks are occurring around the base.

4. Hernia size considerations:
- A small hernia doesn’t necessarily require a change in wafer style. It’s important to monitor for growth and leaks.
- Very large hernias might eventually need surgical repair or a different appliance strategy.

5. Practical next steps:
- Continue using the current flat system as long as there are no leaks.
- If leaks begin or the stoma becomes flatter, consider requesting samples of other convex products from suppliers like Hollister, Convatec, or Coloplast to find the best shape and firmness for a good seal.