Welcome Donna! When it comes to diet, think soft and easy to digest. So, cooked fruits and veggies (no skins) and juiced ones. Whole wheat breads (without a lot of seeds) and pastas are okay and so are soft soy or veggie cheeses. Tofu is good and so is soy milk. Soups are excellent, too. After you heal from surgery, you can introduce some raw foods, but just one at a time in small quantities.
I hope that helps!
I have a jpouch (more complicated than IR surgery) and eat everything; seeds, nuts, popcorn, citrus fruit, pineapple, etc. Please don't look at your surgery as "diet limiting". After a period of recovery you should be able to eat everything that you currently eat; being a vegan should not be a problem.
Oh, and I might add that I eat over 30 grams of fiber per day with no ill effects.