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Digestive Disease Center

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Colon and Rectum

The colon and rectum are part of your intestines, which are long, hollow tubes that run from your stomach to your anal opening. There are two types of intestines: the small intestine (or small bowel) and the large intestine (also called the colon or large bowel). The small intestine connects your stomach to your colon, and your colon then attaches to your rectum and, ultimately, your anus. The colon is about five to six feet long and about an inch or two in diameter.

The function of the colon is to absorb water and store the waste-products of digestion until your body is ready to empty them out. It is shaped somewhat like a large question mark and starts out near your right hip, moves up to your ribs on the right side, goes across to the left side by your ribs, then down to the left hip where it makes an S-curve down to the anus. (See animation video.) The last portion of the colon is called the rectum. At the bottom of the rectum are the sphincter muscles. These muscles prevent the rectum from emptying out accidentally. When a person is ready to have a bowel movement, these sphincter muscles relax and, with straining, the stool is able to be pushed out.

An external illustration of a healthy colon.

Health Maintenance

Some colon and rectal problems can be caused by bowel movements that are either too hard or too loose. Small, hard bowel movements can cut and tear the anal lining. Loose (or semi-liquid) bowel movements do not open the anal canal properly and can stick to and irritate the anal skin. If bowel movements are an appropriate size and consistency, many colon and rectal complaints will disappear.

There are two simple things that can be done to help clear up many colon and anal problems:

  • fiber (natural vegetable powder)
  • proper cleansing
An animation of the colon and rectum.

Natural Vegetable Powder

The simplest way to help give bowel movements the proper consistency is by eating fiber. Fiber acts as a stool normalizer, preventing it from being too hard or too soft. Fiber will help prevent stool from tearing the anal skin and will helps the bowel movements slip out more easily.

Drugstores sell fiber, or natural vegetable powder, without a prescription. It may come in both sugar-free and low-grit varieties, both of which are fine to use. The recommended dosage listed on the container often does not clear up most anal problems. Many doctors, depending upon the brand used, will recommend a dose of three heaping tablespoonfuls —not teaspoonfuls— in water, juice or milk once each morning. Check with your doctor to see if this would be appropriate for your condition.

An internal image of a healthy colon.
An internal image of a healthy colon.

Some people experience cramps when they first start using a natural vegetable powder. If this should happen, cut the dose in half for one week, and then return to the regular dose. If this fails, consider contacting your physician.

When taking fiber, be sure to drink additional fluids whenever you are thirsty. Drinking six to eight full glasses of water or juice daily is recommended.

Cleansing

Be sure to use anal hygiene after each bowel movement to assure that the anal area stays clean.

Toilet paper, which is the most common method to wipe the anal area after a bowel movement, can cause feces to smear over the anal skin. This can result in itching, irritation or other problems. To help prevent these issues, you may wish to use commercially packaged wet "wipes" (cloths) to keep in your purse or pocket. If you do this, look for labels that say "no alcohol, hypoallergenic, fragrance free."

Reviewed by Dr. Pooja Elias (March 2012)

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