Hello, Capetonian. Grains and roughage do not break down (they are insoluable) and so it comes out the way they went in. Nuts and seeds, lettuce, raw carrots, broccoli stalks, cabbage, are insoluable too. They do not break down. They might hurt a lot coming out or cause some constipation, or even diarrhea as your body tries to flush and push out the roughage. Soluable foods break down in your gut. Zucchini (peel the skin!!), mashed or boiled potatoes, fish, egg, cheese, break down easily in your intestines and come out pain free, hopefully. Be careful eating your lentils. Beans can cause problems because of the skin, same as green peas. All the yummy things.....