When and Why to have a
by Dr. Gail Strindberg

olorectal cancer is the second leading cause of cancer deaths in the United States. Fortunately the number of people dying from this type of cancer has been declining. Data shows that greater than 50 percent of this reduction is due to appropriate colo-noscopy screening. However, only about 65 percent of adults age 50 to 75 receive adequate screening.

After age 40 our risk for developing colorectal cancer increases. Developing these cancers is most likely a combination of genetic and lifestyle factors. Having a thorough knowledge of your family cancer history is very important. Having a first degree relative (parent, sister, brother or child) with colon cancer increases your risk of developing cancer. Lifestyle risk factors include, obesity, smoking, heavy alcohol use, a high fat diet, a low fiber diet and a diet high in cooked red meat (two or greater servings per day). Other risk factors include: ulcerative colitis or Crohn’s colitis, diabetes, being male, as well as being Afro American.

We now understand that most colon cancers arise from a benign growth on the inside lining of the colon. These growths are called polyps. There are different types of polyps, that may be detected in a screening but certain ones called adenomas can grow into a cancer. The change from adenoma to cancer is very slow. On the average it takes about ten years for this to occur. About one in five adults over the age of 40 will have adenomas and the risk of developing these polyps increases with age. It has been proven that removal of adenomas prevents colon cancer from developing. If you have a screening colonoscopy and have polyps removed, you are 76 percent less likely to develop cancer than someone who has not had screen-ing performed!

Are There Other Screening Tools for Colon Cancer?

There are several tests that can detect blood in the stool. Blood in the stool can also be a symptom of cancer. These tests are effective at screening for cancer but not for polyps since most polyps will not bleed. If the stool

is positive for blood then the next step should be a colonoscopy. CT scans for polyps and cancer are very accurate as well. But again, any positive finding requires follow up with a colonoscopy.

What is the Risk of this Procedure?

The biggest risk of a colonoscopy is perforation of the colon. The risk of this happening is about 2 in 1000. It is clear that the benefit of removing polyps before they turn into a cancer and of finding a cancer early outweighs the risks of complications in adults aged 50 to 75. However, as people become older than 75 and develop other health problems, it is not as likely that removing a polyp or early detection of a cancer will help them live longer and the results of a complication such as perforation become more serious.

What is Involved?

Having a colonoscopy is a lot easier than most people anticipate. The hardest part is the day before when you have to be on a liquid diet and drink medicine to clean out the colon. This creates the unfortunate need to remain quite close to restroom facilities for the day. The actual procedure itself only takes about 30 minutes and usually you’re in the hospital or ambulatory care center for approximately 2 hours. You are given medicine during the procedure that puts you to sleep—like taking a nap, and makes you forget the procedure. This is not a major anesthesia and there are little to no side effects afterward. Removal of the polyps is not uncomfortable because the lining of the colon does not feel pain. Afterwards you can return to a normal diet. The next day you will be able to return to normal activities.

When should you have your Colonoscopy?

By age 50, everyone should have their first colonoscopy. Screening should continue at least through age 75. Whether screening should continue at age 76 or above depends on the overall health and life expectancy of the

individual. If you have one relative who developed cancer at age 60 or greater, you should still start screening at age 50. If you have had one or more first degree relatives (parent, brother, sister, child) that developed colon cancer before the age of 60 you are considered at higher risk for developing colorectal cancer. In this case screening colonoscopy should begin at age 40 or ten years earlier than when that relative was first diagnosed with colorectal cancer. You should also continue with colonoscopy screening every five years.

If no polyps are found on your first screening you do not need another colonoscopy for ten years. Since we know that having one colon polyp means you can develop more polyps, then more frequent screening is recommended. In general, if you have one or two polyps, have another colonoscopy in five years. If you have three or more polyps, then it is recommended to have an-other colonoscopy in three years. Between scheduled colonoscopies if you develop bleeding from the rectum, notice blood in your stool or develop persistent constipation or diarrhea, be certain to consult your physician.

In Summary

Colorectal cancer is a common disease and cause of death. Fortunately colonoscopy testing is a safe and accurate procedure that not only detects early cancer but is proven to prevent colon cancer from occurring. So please, don’t put it off —a colonoscopy may save your life.


GAIL STRINDBERG, M.D. is a board certified general surgeon. She has been living and practicing in Tooele for the past seven years. She received her medical degree from Columbia University and did residency training at the University of Vermont and University of Pittsburgh. At the time of this writing, Dr. Strindberg is in the process of moving her office to the Northpointe Medical Park.