Low residue is a polite way of saying "don't manufacture lots of poop" The doctors want to limit the size and number of stools you pass giving your intestines and GI system a chance to heal. This means dropping most all fiber out of your daily intake and reducing the quantity of foods your eating to a bare minimum. If I were given this problem I would eat meats, poultry, fish, eggs, watery veggies like yellow and green squash, lettuces, Shirataki tofu noodles, jello, whip cream and lots and lots of liquid to keep everything soft and moving. I would avoid all nuts, peanut butter, seeds, grisly meats, crunchy veggies, strawberries, blackberries, raspberries, fiber and cheese for the next few weeks.
I'm veryhappy that you're reporting that the operation was successful and not a worse report. You'll be OK, just follow the above and doctors advice.