I use Nu-Hope belts. I'm a little guy, so I mostly wear a 3-inch wide belt. I also have a 4-inch wide belt I occasionally wear. They fit excellently and are comfortable to wear all day. Very good quality.
The belts flatten out my peristomal hernia.
The 4-inch wide belt has a prolapse strap. This strap goes across the bag, flattening my protruding stoma. Works well when I wear tighter shirts.
I don't know if belt use will prevent a peristomal hernia or shrink it. It might help to stabilize a hernia, preventing it from getting bigger.
Nu-Hope is located in Pacoima, California. I order the belts from my medical supplier. They are then shipped to me from Nu-Hope.
Many Ostomymates develop peristomal hernia. The ostomy itself is a hernia. If the hernia is not causing trouble and is just unsightly, it's usually left untreated. Repair surgery has high recurrence rates. It's hard to fix.
If your stoma changes color from red to gray, you experience constant pain, or have no output for an extended time, go to the hospital immediately.