Fiber and Bowel Health

Dietary fiber has a definite impact on good health. It now appears that a high-fiber diet may have a preventive effect on cancer of the colon and rectum, cardiovascular disease, diabetes and obesity. The effect on intestinal regularity and diverticular disease is well-established.

Fiber is also important for individuals on a weight loss diet. Many foods that are fiber-rich are low in calories, take longer to chew, and make you feel full for a longer period of time.

About half of all Americans between 60 and 80 -- and a great majority of people over 80 -- have diverticulosis. Diverticulum are small pouches in the colon that bulge outward through weak spots, like an inner tube with weak places. The condition of having diverticula is called diverticulosis. If and when these pouches become inflamed, the condition is called diverticulitis. Between 10 and 25 percent of people with diverticulosis experience diverticulitis.

Doctors believe a low-fiber diet is the main cause of diverticular disease. This disease was first noticed in the United States in the early 1900s. At that same time, processed foods were introduced into the American diet. Many processed foods have much of their fiber stripped from them. They are made from refined, low-fiber flour, which has no wheat bran. Diverticular disease is more common in developed or industrialized countries, particularly in the United States, England, and Australia -- where low-fiber diets are common. This disease is rare in countries in Asia and Africa, where people eat high-fiber vegetable diets.

Fiber is the part of fruits, vegetables and grains that the body cannot digest. Some fiber digests easily in water (soluble fiber), and forms a jelly-like texture in the intestines. Some fiber passes almost unchanged through the intestines (insoluble fiber). Both kinds of fiber help to make your bowel movements softer and easier to pass. Fiber can help prevent constipation, especially in conjunction with adequate fluid intake.

Prevention and treatment of diverticular disease starts with a high-fiber diet. Fiber keeps bowel movements soft and lowers the pressure inside the colon, so that contents move through easily.

You can increase your fiber intake slowly by eating these foods more often:

  • whole grain breads

  • whole grain cereals

  • unprocessed brown rice

  • fruits and vegetables

  • beans and legumes

As you increase the fiber in your diet, be sure to drink plenty of water.

How to Add Fiber to Your Diet

  • Increase fiber gradually. Your stomach and intestines need time to adjust to this change. Too much, too fast can cause gas, cramps and diarrhea; and can discourage your healthy changes.

  • Get fiber from a variety of sources. Experiment with different fruits, vegetables and grains to ensure you're getting a variety of nutrients.

  • Drink lots of water. Fiber acts like a large sponge in your colon, holding water and keeping waste moving. A high-fiber diet can actually constipate you if not accompanied by plenty of fluids. Six to eight 8-ounce cups of water a day should be your goal.

  • Include some fiber at every meal. Breakfast offers a good opportunity for incorporating bran and whole-grain cereals and breads -- along with fresh fruit -- into your diet.

The American Dietetic Association recommends eating between 20 and 35 grams of fiber a day. To meet this daily goal, aim for:

  • 2-5 servings of vegetables

  • 2-4 servings of fruit

  • at least 1-2 whole-grain starches daily (in addition to other grains)

Include beans and other legumes 2-3 times a week.

You can overdo a good thing. Eating more than 50-60 grams of fiber a day may decrease the amount of vitamins and minerals your body absorbs. People usually eat this much by adding wheat bran to foods in addition to large servings of other high-fiber sources.


Americans aren't too eager to eat beans, yet they are packed with fiber and are fat-free. If they give you gas, try these tips:

  • After soaking the beans, discard the soaking water and cook the beans in fresh water; the soaking water contains some of the gas-producing carbohydrates

  • Make sure beans are cooked thoroughly so they are easy to digest

  • Bean-O, available as over-the-counter drops or pills, helps with the digestion of these gas-producing carbohydrates

Try beans in soups, as a filling for tacos or burritos or as a topping on a green salad. Canned beans are available with a number of tasty sauces that can make an interesting side dish.