The small intestine, as we all know is the thin section of the bowel, that starts at the stomach and ends at the large intestine, also called colon. The colon starts in the right side of our lower abdomen and takes the shape of a large question mark across our entire abdomen ending in the rectum. Just above the rectum is the sigmoid (S-shaped) part of the colon. Liquid stool enters the right colon and, as it moves through the colon, is dehydrated so that a formed stool eventually enters the rectum. The sigmoid colon has a very specialized function in our body. It contracts very energetically to maintain a high pressure in the area. This action regulates the movement of stool into the rectum.
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The primary function of a healthy colon is to complete the digestion process. The colon does this by removing excess water from food wastes entering from the small intestine enabling it to absorb enough water. If water can not be absorbed properly and stool passes through the intestines too rapidly, watery stools and diarrhea result. On the contrary, if the passage of waste is very slow, too much water is absorbed. This results in hard stools and constipation, which often leads to straining. These simple problems occasionally lead to more serious disorders.
Fiber (also called roughage or bulk) promotes wavelike contractions, also called peristalsis, that keep food moving through the intestine. Also, high-fiber foods expand the inside walls of the colon and helps maintain good colon health. This makes the waste matter to pass through easily. Fibrous substances pass through the intestine undigested. They also absorb many times their weight in water, resulting in softer, bulkier stools. Fiber-rich diet can also help absorb all the toxins and harmful bacteria which has a habit of accumulating in the colon, if left unattended for a long time.
Colon cancer is a major health problem in the United States. What today is a colon polyp, a benign mushroom-shaped growth, may develop into colon cancer tomorrow. If colon polyps are detected and removed early, colon cancer can be prevented. While colon cancer can be hereditary, a fiber-rich diet can help in its prevention too. It is widely believed that in Western food habits, cancer-containing agents (carcinogens) remain in contact with the colon wall for a longer time and in higher concentrations. Thus a large bulky stool may dilute and expel these carcinogens by moving them through the bowel more quickly. Less carcinogenic exposure to the colon may mean fewer colon polyps and less colon cancer.