How to keep your colon clean and healthy

Understanding its vital role in digestion, absorption, excretion, and immunity

Globally, colon cancer ranks fourth in the leading causes of cancer-related deaths, according to the World Health Organization (WHO). In the Philippines, it is also the fourth leading cause of cancer-related deaths. Colon cancer can be hereditary in nature and it can also be developed through unhealthy lifestyle. The good news is that it can be prevented, through proper screening tests that can remove abnormal growths in the intestinal lining called polyps, as well as lifestyle changes.


The colon is part of the body’s digestive system, which begins with the mouth all through the anus. More specifically, the U-shaped tube that is approximately 1.5 meters long comprises one-fifth of the large intestine together with the appendix, cecum, and rectum where stool or feces is excreted out of the body through the anus.

When a person eats, digestion begins in the mouth where enzymes are produced to start breaking down carbohydrates. It travels down to the stomach to be mixed and broken down into smaller portions to be passed down to the small intestine where further digestion occurs. Ninety-percent of the food and nutrients get digested and absorbed as fuel or energy source in the small intestine. The remaining nutrients, water, and indigestible food materials, also known as fiber, pass to the colon. 

The colon absorbs water, electrolytes like potassium, and vitamins. It forms stool in preparation for excretion through the rectum. Moreover, the colon has the Herculean task of breaking down indigestible matter in the form of fiber through the process of fermentation aided by friendly bacteria, which make up what we call the gut microbiome. This results in the production of short chain fatty acids that support the growth of beneficial bacteria. These beneficial bacteria are not only involved in digestion but largely contribute to the immune system, mental health, and overall prevention of diseases that stem from chronic inflammation in the body, such as heart diseases, diabetes, allergies, diseases of the joints, and even cancer. 

To keep the colon clean and healthy in order to prevent colon cancer and other diseases that are impacted by the gut microbiome, eating lifestyle must primarily be addressed. The most important thing is to avoid or at least reduce consumption of red meat and processed meats. Red meat includes beef, pork, lamb, mutton, veal, venison, and goat. Processed meat include meat that has been cured, smoked, salted, or those with preservatives added like tapa, tocino, longganisa, bacon, ham, sausage, deli meats, luncheon meat, corned beef, hotdog, and other canned meat that may also include chicken and turkey.

A systematic review and meta-analysis of prospective studies on the consumption of red meat and processed meat and cancer incidence conducted by Maryam S Farvid et al was published on Aug, 29, 2021. It was shown that high intake of red meat was positively associated with increased risk for colorectal, colon, and rectal cancer in addition to cancers of the breast, endometrium, lung, and liver. Furthermore, high total intake of red and processed meat increases the risk of colorectal, colon, rectal, lung, and kidney or renal cancers. 

With red and processed meat out of the way, the next thing to do is to make sure that fiber is a staple in your daily diet, possibly in every meal. Fiber is only available in plant food sources, such as fruits, vegetables, whole grains, nuts, and seeds.

Not all fibers, however, are created equal. It is the soluble fiber that gets fermented in the colon or gut that acts as food for good bacteria for them to thrive and proliferate. The best sources of soluble fiber are oats, psyllium husk, mushroom, soy, beans, lentils, peas, onion, garlic, banana, apple, guava, avocado, pear, eggplant, carrot, sweet potato, broccoli, barley, and other fruits and vegetables. Soluble fiber forms a gel-like structure with water. This delays the transit of food in the digestive system, making one feel fuller longer. This aids in weight management. It also helps lower cholesterol and blood glucose. This is helpful as well when one is experiencing diarrhea.

The other type of fiber is insoluble. In contrast to soluble fiber, insoluble fiber adds bulk to the stool and makes food pass more quickly through the stomach and intestines. This type of fiber acts as a broom in the colon keeping it clean by regulating bowel movement. Insoluble fiber is found in fruits and vegetables, as well as wheat bran and other whole grains like quinoa and brown, red, and black rice.

If you want to keep your colon clean and healthy, make sure to consume a variety of plant food sources and keep yourself well-hydrated throughout the day. Intake of fiber coupled with inadequate water consumption could lead to constipation.