A year of ostomy supplies would be great. Although there are re-usable ostomy pouches.
Huge fan of WD by the way. I would think from watching the show, everyone would be smelling a little rank about now without a daily shower. I would be more worried about stomach skin acid burns being an ileostomate. But you can create make shift pouches out of many things. Condom's come to mind. Not ideal but good in a fix.
On a serious note, the closest we might come to a zombie apocalypse would probably be a mutated version of rabies similar to the movie 28 days later. I'd be screwed. I have about a month of supplies at any given time. But I have a 12 guage shotgun with a shxtload of ammo.
YOU CAN HAVE MY OSTOMY SUPPLIES WHEN YOU PRY IT FROM MY COLD DEAD STOMA!!