@Guzzler - with a low residue diet you are aiming for as little fibre/roughage as possible in the diet. It is designed to minimise bowel movements. My dad had bowel cancer and from the time of diagnosis to surgery he had to follow this diet. I recall that he could eat veg grown below the ground but it had to be peeled. No cabbage/cauli type veggies, no beans, pulses or anything else that encourages bulky bowel movements.
However, he was expected to have cream, cheese, and easy-to-digest meat, I remember mum swirling cream into soup, and sprinkling mashed spuds with grated cheese. She had to peel all the veg too.
ETA - I can't remember much more than that - sorry. I didn't live with them at that time, and am going from visits and phone conversations.