Dietary Fiber

Introduction
Patients with colorectal or anorectal problems are generally unaware of how their own bowel habits may vary from normal. Since their problems usually stem from childhood, representing lifelong habits, and since they have no standards for comparison, most patients assume that their function is normal.

Most patients who develop colon cancer, diverticulosis, diverticulitis, hemorrhoids, fistula and fissure have had a lifelong history of difficulty with their bowels. In most instances, they suffer from chronic habit constipation.

The usual cause of chronic constipation is a lack of adequate dietary fiber. Dietary fiber is generally obtained from plant foods, and consists of that portion of the plant which is not digested by man. While the sugars, starches and vitamins are broken down into nutrients and are absorbed by our intestines, the cell walls are not digested and go on to form an important component of the stool, the bulk or roughage. An example of dietary fiber is cellulose, and a food which is high in fiber is wheat bran.

Correcting the fiber inadequacy in one's diet will help one to achieve normal bowel movements and normal bowel habits. If damage has taken place, as in the development of diverticulitis, the adjustment of one's dietary fiber intake may prevent further deterioration of the damage over time. The decision as to how much fiber to use in the face of pre-existing conditions should be made in consultation with your doctor.

For the bowels to work properly, a lifelong daily intake of 25-30 grams, or about one ounce of dietary fiber daily, is required. After the digestion of all proteins, fats and carbohydrates, and the absorption of water and other nutrients in the small intestine, the colon (the last five feet of the intestine) receives approximately one pint of liquid stool together with the undigested fiber.

Under normal circumstances, the colon gradually removes the remaining water, and forms a shaped stool, which moves toward the rectum as a result of gentle pressure waves. In people who eat too little of fiber-containing foods, the stool becomes hard, dry and small. Whereas the soft, bulky stool can move easily along the passage of the colon, the hard, dry stool sticks to the dry wall of the colon and requires that the colon develop high-pressure waves to be moved. Years pass, and the colon is no longer capable of generating such high pressure waves. The colon now requires assistance to push along the hard, dry stool, and the abdominal muscles begin to contribute the necessary force. This we call "straining." The straining produces pressure on all of the abdominal wall, forcing the development of hernias, varicose veins (due to pressure on the long veins of the legs), hiatus hernia (upward pressure forcing the stomach into the chest), diverticulitis and diverticulosis (weakening and infection of the colon wall), hemorrhoids, anal fissures and fistulae. Colorectal cancers may also be more common in patients with lifelong habit constipation. This may be due to the concentrated exposure of carcinogens to the colonic surface, as a result of the hard dry stool and its slow movement or evacuation.

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Normal Bowel Habits
It is normal for one to have one or two soft, formed easily passed bowel movements a day, without any effort or straining. The British term is a "bowel action," and literally one should be able to evacuate promptly and easily. This is not the case for most Americans, some of whom have the best "bathroom libraries" in the world, and some of whom actually reserve this time for reading the daily newspaper-cover to cover. The habit of reading in the bathroom is simply a reflection of inadequate function.

It is not normal to miss moving one's bowels on any given day. It is not normal to solve the problem by taking a laxative. If your bowels move daily, but with difficulty or straining, if your stool is dry or hard, or if you don't move your bowels daily, you need to adjust your diet for the right amount of fiber intake.

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Normal Physiology
When there is adequate fiber in the diet, the fiber (viewed as millions of tiny water attracting particles) mixes with the stool. Each particle soaks up available liquid, and enlarges into a minute gel bead. These particles give the stool size shape and moisture, making it easy for the colon to move along easily.

To work properly two other circumstances must also be right; adequate water for absorption, and adequate lubrication of the colon lining. We require 8-10 (8 or 10 ounce) large glasses of water daily. Water can be any liquid, whether it is tea, coffee, milk, fruit juices, soft drinks, or other beverages that agree with you. Milk products may be particularly gassy, due to the fermentation of milk sugar, i.e., lactose, in the colon.

In order to lubricate the passage, the colon manufactures mucous. If the colon is dry, i.e., one has too little mucous, or drinks too little water, the stool will be hard and dry and will stick to the colon requiring that one strain to eliminate.