Your large intestine is one of the last stops digested food material makes before exiting your body. While the small intestine is generally considered the digestive organ that absorbs the most nutrients, the large intestine does absorb some nutrients while also removing water and absorbing wastes. Understanding the work of the large intestine can help you recognize some of the symptoms you may experience if this organ is not working properly.
Fiber is a form of carbohydrate that remains largely undigested in your small intestine because it takes longer than most nutrient forms to digest. However, your large intestine is home to more than 500 forms of healthy bacteria that can digest some forms of fiber in a way that your small intestine cannot, according to the University of Waikato. For example, bacteria present in the colon can digest some fiber portions and turn it into fatty acid chains, which are then used for energy production. Fibers that can be digested include pectins, which are found in foods such as apples and citrus fruits. Fiber is responsible for absorbing and attracting water as it moves through your digestive system. Your colon, which is the major portion of your large intestine, is responsible for absorbing this water back into your body.
Your large intestine moves salts into your blood vessels via a process known as osmosis. Your body needs these salts to adequately function because salts are responsible for nerve and muscle transmissions that keep your heart beating and lungs inflating.
The large intestine contains bacteria that interact with undigested food material to produce needed vitamins for your body. For example, the bacteria in your large intestine work to create vitamin K, which is necessary for blood clotting. If you do not have enough of this vitamin, you are more likely to experience bruising and excess bleeding.
The process of absorbing these nutrients and water can sometimes have an unwanted side effect -- release of gases. When the bacteria in your large intestine ferment undigested food material, such as fiber, they can release carbon dioxide, hydrogen and methane gas. In some instances, this can cause increased amounts of flatulence or the expulsion of gases from your rectum. If you experience flatulence that is embarrassing or progressively increases in amount, speak to your physician.
- KidsHealth: Digestive System
- Children's Hospital of Pittsburgh of UPMC: Organs: Small and Large Intestines
- The University of Waikato: Large Intestine Function
- MedlinePlus: Vitamin K
- Texas A & M University: Digestive System
- Linus Pauling Institute: Fiber
- Go Ask Alice! at Columbia University: Pectins (Soluble Fiber)
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