Colon (Large Intestine) Function in Digestive System

What does the colon do? Why is it important? And how can you make sure it stays healthy?

The colon, also known as the large intestine, is responsible for absorbing water from food and nutrients. It also helps remove waste products from the body.

If you’ve ever had diarrhea, constipation, or gas, then you already know that the colon plays a big role in keeping our digestive system running smoothly. In fact, many doctors believe that the health of the colon is just as important as the health of the heart.

This article will cover everything you need to know about the colon and its function in a healthy digestive system. This will help you understand why it’s important to keep it healthy.

Where is the Colon Located?

The colon is the last part of the digestive system, which begins at the mouth and ends at the anus. The colon is about 1.5 meters long (4.92 feet) and about 6 cm (2.36 inches) in diameter. 

The colon is shaped like an inverted U, made up of three main sections, located inside the abdominal cavity – the colon, rectum, and anus. 

The beginning of the large intestine is the cecum. The cecum starts in the lower right quadrant of the abdominal cavity, and then the ascending colon runs up the right side of the body to just below the liver.

From here, it travels across the abdomen (transverse colon) to the body’s left side, descends down (the descending and sigmoid colon), and ends at the rectum/anus.

What is the Function of the Colon?

The colon is responsible for the final stages of the digestive process.

The colon has three main functions:

  1. To absorb any remaining water and electrolytes from indigestible food matter
  2. To absorb and store undigested food remains that were not absorbed by the small intestine, like vitamins and minerals
  3. To eliminate solid waste (feces) from the body.

The colon helps keep the body’s fluids balanced. It helps break down some foods and absorb certain vitamins, and processes some indigestible materials (like fiber) before they’re eliminated.

The formation of feces (stool) starts in the colon. Fiber, small amounts of water, and vitamins mix with the mucus and bacteria living in the large intestine. 

As the feces travels through the colon, the intestinal wall absorbs most of the water and some of the vitamins and minerals present. Colon bacteria feed on the fiber, which they break down into nutrients that nourish the cells lining the colon. That’s why fiber is so important for the colon’s long-term health.

Feces moves along the large intestine until the walls of the sigmoid colon contract, forcing the waste to move into the rectum. This is known as peristaltic action, a wave-like motion that encourages feces to move closer to the rectum until it is expelled through the anus with a bowel movement.

Why is a Healthy Colon So Vital?

The colon absorbs vitamins and minerals, salts, and nutrients. When our bodies are properly absorbing these essential, life-giving nutrients, it makes us feel good. But when the colon isn’t working properly, it absorbs toxins into the bloodstream rather then expel them.

The colon is home to a zoo of gut bacteria, a microbiome. Over one hundred trillion microorganisms (bacteria) live there. The colon contains more microorganisms than there are in the skin, bone, heart, brain, and the rest of the body combined.

To ensure that you don’t suffer from constant digestive ailments, you need to maintain a proper balance of healthy bacteria inside your colon.

The world we live in today places a serious toxic burden on the colon. Most of the food we eat lacks nutrients and is often full of additives, preservatives, and other chemicals. 

Everything in the world today, from the air we breathe and the water we drink, to the thousands of chemicals that we come into contact with every day, affects our colon and overall health.

A Delicate Balance

The delicate balance of the specialized cells of the colon and microorganisms (bacteria) in the gut can easily be upset by:

If digestion and colon function are working poorly together, the body operates in a state known as auto-intoxication. This means that the body is working hard to eliminate toxins, but it cannot keep up because the toxins are being recycled (reabsorbed), instead of expelled.

A poorly balanced colon may contribute to chronic diseases, including:

  • Arthritis
  • Asthma
  • Irritable Bowel Syndrome (What is IBS Pain Like?)
  • Heart Disease
  • Colon Cancer, Colorectal Cancer

To avoid long-lasting health issues, it’s important to keep your colon functioning properly.

How Can I Keep My Colon Healthy?

You can help prevent problems in the colon by maintaining a healthy diet. Avoid foods high in sugar, salt, or unhealthy fats. Try eating plenty of vegetables and fruits, whole grains, beans, nuts, seeds, and lean meats.

These are the main tips to keep in mind to maintain a healthy colon and gut: 

Eat More FiberA diet rich in fiber helps promote regularity, protect against disease, and improve digestion.

Eat Healthier Fats – Fatty acids found in fish oil support normal intestinal function and reduce symptoms of Irritable Bowel Syndrome. Red meat and colon cancer have also been linked in studies.

Drink More Water – Drinking enough water keeps the colon clean and helps flush out toxins. Water helps to keep your digestive system working well.

Avoid Alcohol – Alcohol reduces the ability of the colon to absorb water. It also increases the risk of colorectal cancer.

Colon Function Final Thoughts

All in all, the colon plays an integral role in maintaining a healthy lifestyle. It helps regulate blood pressure, controls weight, and regulates hormones. If you want to enjoy optimal health, you must take care of this important organ.

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Colon FAQs

What are the four major functions of the colon?

The four major functions of the colon (aka large intestine) are to absorb remaining water and electrolytes from undigested food, form and store vitamins and minerals, and to form and eliminate feces from the body. 

Does the colon have a digestive function?

The colon, also known as the large intestine, is responsible for absorbing nutrients from undigested foods and processing them into feces to expel from the body. The colon does that by absorbing water and electrolytes, and anything else not digested by the small intestine. The bacteria in the colon then feeds on the fiber to break down those nutrients to produce feces.

Can a person live without a colon?

A person can survive without a colon, but it would be very difficult. The human body needs a healthy colon to function properly. Without a healthy colon, the body will suffer from constipation, diarrhea, gas, bloating, cramps, and other symptoms. A healthy colon is essential for proper digestion, absorption of nutrients, and elimination of waste products.

Julie C. Guider MyGoodGut

Medically reviewed by Julie Guider, M.D.

Dr. Julie Guider earned her medical degree from Louisiana State University School of Medicine. She completed residency in internal medicine at the University of Virginia. She completed her general gastroenterology and advanced endoscopy fellowships at University of Texas-Houston. She is a member of several national GI societies including the AGA, ACG, and ASGE as well as state and local medical societies.