Sorry to hear about your situation, Gin. Sounds frustrating, indeed. Can I ask what the surgeon's explanation is for the issues that apparently resulted from the pouch advancement? Curious, as my surgeon as suggested a PA due to my fistula....
I'm not a long-term low residue dieter, but perhaps have a few ideas in addition to Sharon's. Instead of oatmeal, there are other hot cereals such as cream of wheat, and malt-o-meal (even chocolate malt-o-meal!), etc. Both with honey drizzled on, pretty good.
And -- avocados. Smash them and put them on toast, whole as garnishes, or wrap them in a piece of turkey or other deli meat. IMO, when smashed, they need nothing added outside of a little salt, but a tiny bit of lime juice is nice. If you have a low-spice salsa that you can handle, that's good mixed in as well.
Meats prepared in a crockpot might be a little easier on the "system", again - IMO. They get broken down to a tender, melty consistency (chicken, turkey, roast beef).
Good luck with the diet, and all the other things going on in your life. Keep us updated?