High Fiber Diet 

The primary function of the colon is to complete the digestion process by removing excess water from food waste that enters from the small intestine. When waste moves through the intestines too quickly, not enough water is absorbed, leading to watery stools and diarrhea. Conversely, if the waste moves too slowly, too much water is absorbed, resulting in hard stools and constipation, which can cause straining. These common issues can sometimes lead to more serious disorders.  

Fiber, also known as roughage or bulk, plays a crucial role in promoting the wavelike contractions that help move food through the intestine. High-fiber foods expand the inner walls of the colon, which facilitates the passage of waste. Fibrous substances pass through the intestine undigested and have the ability to absorb many times their weight in water, resulting in softer, bulkier stools.

Studies indicate that rural Africans, who consume diets rich in fiber, eliminate food waste in one-third of the time it takes individuals in urban, Westernized cultures. Their stools are larger and softer. This increased bulk and faster transit of food through the digestive tract likely help to sweep away harmful substances before they can cause health issues. As a result, these rural populations tend to experience fewer digestive tract diseases commonly found in Western nations, which may be linked to their dietary habits.

A high-fiber diet leads to the production of large, soft, bulky stools that pass through the bowel easily and quickly. This process can help prevent, halt, or even reverse some digestive tract disorders simply by following a high-fiber diet. Softer, larger stools help prevent constipation and straining, which can alleviate or prevent hemorrhoids.

Increased bulk in the diet reduces pressure in the colon, which is important for treating conditions like irritable bowel syndrome and diverticulosis (defects in the weakened walls of the colon). Additionally, fiber is believed to play a significant role in managing diabetes, lowering cholesterol levels, and reducing the risk of colon polyps and colon cancer.

The High Fiber Diet can be nutritionally adequate as long as a balanced selection of foods from each of the basic food groups is included. Some studies suggest that excessive intake of certain sources of dietary fiber may bind to minerals and interfere with their absorption. These minerals include calcium, copper, iron, magnesium, selenium, and zinc. However, adults who follow a balanced and regular diet generally do not experience problems. In some cases, a physician may prescribe supplements.

Irritable bowel syndrome (IBS) is one of the most common disorders of the lower digestive tract. There is no disease present with IBS, but it creates bothersome symptoms such as altered bowel habits -- constipation, diarrhea, or both alternately. There may also be bloating, abdominal pain, cramping, and spasms. An attack of IBS can be triggered by emotional tension and anxiety, poor dietary habits, and certain medications. Increased amounts of fiber in the diet can help relieve the symptoms of irritable bowel syndrome by producing soft, bulky stools. This helps to normalize the time it takes for the stool to pass through the colon. Liquids help to soften the stool. Irritable bowel syndrome, if left untreated, may lead to diverticulosis of the colon.  

Colon cancer is a significant health issue, particularly prevalent in Western cultures. Most cases of colon cancer begin as colon polyps, which are benign, mushroom-shaped growths. Over time, these polyps can grow, and in some individuals, they may become cancerous. If polyps are removed when detected or if surgery is performed at an early stage, colon cancer is usually curable.

Research suggests that genetics can play a role in an individual's risk of developing colon cancer; however, diet is also an important factor. In countries where grains are minimally processed and retain their fiber, the rate of colon cancer is very low. The prevailing theory is that in the Western world, cancer-causing agents (carcinogens) come into contact with the colon wall for extended periods and at higher concentrations. A larger, bulkier stool may help dilute these carcinogens by moving them through the bowel more quickly. Reducing exposure to carcinogens may lead to fewer colon polyps and a lower risk of cancer.

Prolonged and vigorous contractions of the colon, particularly on the left lower side, can lead to diverticulosis. This condition increases pressure in the colon, causing small balloons or pouches to form. While these pouches typically do not cause problems, they can sometimes become infected (a condition known as diverticulitis) or even rupture (perforate), which can lead to infection or inflammation of the abdominal lining (peritonitis).

A high-fiber diet can increase the bulk of stool, which may help reduce pressure within the colon. As a result, the formation of pouches could be decreased or even halted. Some healthcare professionals recommend avoiding certain foods in diets for diverticulosis, including nuts, poppy seeds, caraway seeds, rye seeds, popcorn, crunchy peanut butter, corn, cucumber, and squash, along with fruits and vegetables containing seeds such as strawberries, figs, and tomatoes. However, there is no medical evidence proving these foods are harmful. Many gastroenterologists permit and even encourage their consumption, depending on the individual's tolerance.

Insoluble fiber is found in wheat, rye, bran, and various other grains. It is also the type of fiber present in most vegetables. Insoluble fiber does not dissolve in water and cannot be used as a food source by the beneficial bacteria in the intestines and colon, which means these bacteria typically do not grow or produce intestinal gas as a result.

In contrast, soluble fiber dissolves in water, forming a gel-like substance in the bowel. It is found in foods such as oatmeal, oat bran, fruits, psyllium (found in products like Metamucil and Konsyl), barley, and legumes.

One of the key benefits of soluble fiber is its ability to bind cholesterol, facilitating its elimination through stool. If enough cholesterol is removed, soluble fiber can lower blood cholesterol levels by 10-15%. However, a downside of soluble fiber is that it can be metabolized by gas-producing bacteria in the colon. While these bacteria are harmless, individuals who experience intestinal gas or flatus may want to limit their intake of soluble fibers to determine if they contribute to these issues. 

Ideally, both soluble and insoluble fibers should be consumed daily for optimal health.

Some people have difficulty tolerating fibrous foods. If you're unable to get enough fiber through your diet, there are several stool softeners and bulking agents available. These products absorb water and produce the bulk necessary for the digestive tract to function properly, helping to create soft and well-formed stools. As a result, they can be very useful in preventing and treating digestive disorders. Some examples of these products include Metamucil, Konsyl, and Per Diem Fiber, which all contain psyllium mucilloid derived from the seeds of the psyllium plant. Other bulking agents, such as Citrucel (which contains hemicellulose) and FiberCon (which contains polycarboxylic acid), can also be effective.

Aim for a daily fiber intake of 25 to 35 grams. Below are common servings of foods that are rich in dietary fiber. To boost your fiber consumption, incorporate a variety of sources. Keep in mind that foods from the meat and dairy groups do not provide significant amounts of fiber. Generally, foods that are high in fiber are also low in fat.