Do I Really Need to Have a Colonoscopy?

January 15th, 2013 by Eduardo Krajewski, MD, FACS, FASCRS

Many people worry about cancer and cancer prevention, especially colon cancer. Colon cancer is the third most diagnosed cancer in the world, and it is the fourth most common cause of cancer death. But the death rate from colon cancer has been dropping over the last 15 years. This is probably due to improved screening and early detection.

Early Detection Makes a Big Difference

When colon cancer is detected early, there is a five-fold increase in the survival rate. Colon cancers are in an early stage if they are detected before penetrating the muscular layer of the large intestine. The five-year survival rate for these cancers is 100%. However, once the cancer has spread throughout the body the survival rate drops to 5%. At the early stage you normally don’t feel or see anything that would make you realize you have cancer. That is why screening is important.

Colonoscopy Can Save Your Life

A screening colonoscopy could save your life. It could detect an early stage colon cancer before any signs or symptoms appear. It you wait until you are sick, then your chances for survival go way down. Some studies have shown early detection with colonoscopy cuts in half the risk of death from colon cancer.

The American Cancer Society recommends various options for the screening of colon cancer. One of these is the screening colonoscopy every ten years starting at age 50. If you have a personal or family history of colon cancer or polyps, then screening should begin earlier. Also if you have ulcerative colitis or Crohn’s disease, you are at higher risk and should have a screening colonoscopy done earlier.

Exactly how is a Colonoscopy Done?

A colonoscope is basically a camera that is placed at the end of a long flexible fiber optic containing tube. This tube is inserted into the anus and moved forward. The end that the surgeon holds has controls that allow for the visualization and filming of the insides of the large intestine. The device also can pump air into the intestines, and it can take biopsies using special instruments that extend from the tip of the scope.

Is Colonoscopy Painful?

The procedure has some discomfort but mostly due to the air pumped into the intestine. This is done to smooth out the bumps and wrinkles of the bowel. In the United States, the procedure is usually done with some type of anesthesia, either partial or complete. In Europe, the procedure is often done with no anesthesia at all.

How do I Prepare for Colonoscopy?

The intestines must be clean in order for good visualization. Typically you are put on a clear-liquid diet for 1-3 days before the procedure. The day before the colonoscopy you are given a special laxative preparation that cleans out the bowel completely. Also you might be asked to drink a special bowel irrigation preparation. All of this is intended to cleanse the large intestine so that it can be examined completely and clearly by the surgeon.

What are the Advantages of Colonoscopy Compared to Other Screening Tests?

There are other colon cancer screening tests such as sigmoidoscopy, fecal occult blood testing, virtual colonoscopy and barium enemas. Each physician has his or her preference. The advantage of colonoscopy over these other methods is that the entire large intestine is visualized directly. Also, it there are any suspicious polyps, they can be biopsied and sent for examination right away without having to do another procedure.

Is Colonoscopy Safe?

Colonoscopy is very safe. The biggest risk is that the colon becomes perforated or punctured. This rare complication requires emergency surgical repair. Overall, the risk of serious complications is very low at around 0.35%.


Colonoscopy is recommended for the routine screening of colon cancer. It is very safe and well tolerated. When detected early, colon cancers are curable, so it is important to be screened starting at the age of 50 or earlier.


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