Function of the Large Intestine in Digestion

Our body absorbs essential nutrients from the food through the process of digestion. Various nutrients like proteins, fats, and carbohydrates cannot be assimilated into the bloodstream in their complex molecular forms. To get absorbed into the blood, they need to be broken down into simpler forms.

For example, proteins need to be broken down into amino acids, carbohydrates into polysaccharides and monosaccharides, fats into fatty acids and glycerol.

This is done by various digestive enzymes. The nutrients, that are thus obtained, are then easily absorbed into the bloodstream. Through blood, they are transferred to each and every cell of the body.

The waste material or the fecal matter is then thrown out of the body. The process of digestion involves various stages, and accordingly, the organs of the digestive system have specific functions to perform.

The large intestine starts where the small intestine ends, and this happens in the region just below the waist in the right side of the human body.

The cecum then continues to the ascending colon that rises up through the right side of the abdomen. The ascending colon runs horizontally through the abdominal cavity. Here, it is known as the transverse colon.

The transverse colon finally descends down the left side of the abdomen as the descending colon. The descending colon ends in the rectum and the anus, which are the last sections of the digestive tract.

Functions of the small and large intestines are different.

➺ As far as digestion is concerned, no further breaking down of food takes place in the large intestine. This step is completed in the stomach and small intestine.

➺ The main function of the large intestine in digestion is to absorb salts and water from the chyme (slurry of the digested food), and pass the waste material on to the rectum for excretion. Absorption of water helps maintain the fluid balance of the body. The body can use the retained water for various metabolic purposes.

➺ The large intestine helps process undigested material like fiber. The material that reaches the large intestine is fecal matter, as the process of digestion and absorption of most of the nutrients is almost completed in the small intestine. Absorption of water and salts from the fecal matter in the large intestine makes the stools solid and compact.

➺ Large intestine helps absorb certain vitamins. The colon is home to certain friendly bacteria. These bacteria manufacture vitamin K that is vital for the blood clotting process. Vitamin K is almost exclusively produced by these bacteria.

➺ The small intestine passes the chyme to the large intestine. Here, the bacteria digest the substances that are not digested by the stomach and the small intestine. Bacterial fermentation eventually converts the chyme into feces. This process results in the release of vitamins, such as vitamins K, B1, B2, B6, B12, and biotin.

➺ Besides this, bacterial fermentation also leads to release of gases such as carbon dioxide and methane. While promoting the movement of the chyme and the feces (peristalsis or a series of organized contraction of the muscles of the intestines), these gases also lead to flatulence. They are passed through the anus.

The amount of these 'friendly' bacteria depends upon the foods consumed. Antibiotics often kill them. An infection due to lack of these bacteria or due to presence of 'bad' bacteria in the colon hinders absorption of water from the stool, and results in diarrhea.

➺ Another obvious function of the large intestine is to simply store the fecal matter till it is eliminated from the body through the anus.

Absorption of water and salts, and storing waste material till they are thrown out of the body are what large intestine functions in digestion include. As the fecal matter is stored in this organ, some of it may stick to its walls. Buildup of toxic material in the intestine may lead to problems of the colon and other complications.

Colon cleanse is a treatment by which the large intestine can be cleaned of all the toxic materials. This treatment is becoming quite popular nowadays, as its detoxifying effects benefit the whole body.

Large intestine functions complete the aim of the digestive system, which is to break complex nutrients into the simpler forms, absorb the nutrients, and get rid of the waste material from the body.