Yes, you can get stoma plugs in the US. Liberator Medical has them--they're in Florida and have since been bought out by Bard. If you key Liberator Medical, it will probably redirect you to the new site. They sent me a bunch of samples--but didn't like any of them except the Unisolve adhesive remover. Lots of weird filter systems and convex bags, which I don't need.
Before you get a plug, check with your Ostomy nurse and your surgeon. When I was in rehab (not a good choice), one of my ignorant and untrained nurses said that 14 years ago when a patient needed to 'stem the tide' while changing an appliance, they would use an OB TAMPON (guys, that's just a tampon without an applicator) sliding it halfway in to stop any flow.
My Ostomy nurse had heard of this practice but will not allow her patients to do it. My surgeon went ballistic. He hates stoma plugs. Why, you ask? Because it stops the natural flow and can cause a backup (uncomfortable) or a BLOCKAGE. For those of you who've had a blockage, I need say no more. My surgeon's practice is comprised of more blockages than he cares to handle—he said it's like removing a block of concrete from a human body.
Not nice for anyone. I haven't asked him about irrigation yet, but I know he would tell me to use a waterproof stoma cap to contain any natural fluids. Your stoma is a one-way valve meant to keep your system clear. Don't back it up or block it.