The high residue (high bulk, high fiber, high roughage) diet is indicated in atonic constipation, spastic colon, irritable bowel syndrome, and diverticulosis. This diet encourages regular elimination by stimulating muscle tone, creating softer and larger stools that are more easily propelled through the colon. This reduces the pain and cramping that accompany spastic colon or irritable bowel syndrome.

The patient is given a regular diet, with the inclusion of high residue foods. The main sources of fiber are whole grain breads and cereals, bran cerals, fresh fruits, and vegetables that are raw or cooked until tender. Whole grain breads and cereals that contain wheat bran have a greater laxative effect than fruits and vegetables, because the bran acts to absorb water within the colon creating, a bulk effect. At least one serving of 100 percent wheat bran cereal is recommended daily. Raisin Bran, Bran Flakes, Shredded Wheat, and Oatmeal may be used occasionally, but they contain less than half the amount of fiber in All Bran or Bran Buds. Fresh fruits and vegetables with edible skins, such as apples and grapes are higher in fiber content than canned fruits or vegetables and their juices.

Dietary intake of refined sugars and starches should be decreased, as they are poor sources of fiber. Limit white flour products, refined cereals, pies, cakes, and cookies.

Fluids are increased. Too little fluid in the diet may cause dehydration and lead to constipation. The patient must drink at least 8 glasses of water or other fluids daily, particularly when consuming the recommended amount of bran. Drinking too much alcohol, coffee, cola, tea, and soft drinks can irritate a sensitive colon and can cause dehydration. If possible, use decaffeinated coffee. One or 2 glasses of water in the morning helps to stimulate peristalsis.

Excessive intake of alcohol, beverages containing caffeine (coffee, tea, colas), chili powder, dried beans, fruits with seeds and skins, nuts, pepper, popcorn, and strong spices may cause irritability. These foods should be individualized to the patient.

When one is progressing from a low residue diet after an acute infection or diverticulitis, increase fiber in the diet gradually. Start by adding 1 serving of 100 percent bran cereal and 3 servings of whole grain bread to the low residue menu pattern. Gradually increase the amount of raw vegetables and fresh fruits to at least 4 servings per day.