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Gastroenterology (GI) Education

Colon Cancer and Colon Cancer Screening


Here are some statistics you may find important to know:

  • An estimated 670 people will die from colorectal cancer in Oregon this year alone
  • Nearly 147,000 people in the US will be diagnosed with colorectal cancer in 2009
  • 6% of men and women will develop colorectal cancer in their lifetime
  • 1 in 3 over age 50 will have polyps
  • Colon polyps have no symptoms in most cases
  • Colon cancer often occurs without symptoms until later stages
  • Currently only 50% of Oregonians have had screening

The colon is the part of digestive system where the waste material is stored. The rectum is the end of the colon adjacent to the anus. Together, they form a long, muscular tube called the large intestine (also known as the large bowel). Tumors of the colon and rectum are growths arising from the inner wall of the large intestines.

Colonoscopy is the single best test for colon cancer screening and
allows your doctor to look at the inner lining of your large intestine (rectum and colon). The goal is not only to look for colon cancer, but to find and remove polyps at the time of the exam. Removing these polyps is the most effective way to prevent colon cancer.

The National Polyp Study has shown that polyp removal with colonoscopy surveillance program can reduce the risk for colon cancer by up to 90%.

Colon cancer generally does not have symptoms until later stages. Symptoms can include spotty rectal bleeding, a change in bowel habits, vague abdominal pain, unexplained weight loss, fatigue, or laboratory disturbance such as anemia. These symptoms are not specific or reliable, so waiting until they occur before deciding to have a colonoscopy is not recommended. Besides, a late diagnosis can dramatically impact chance for survival.


Please call your primary care provider to schedule your annual physical and discuss a referral for a colonoscopy if you have not yet had one. You may also call our office if you have questions about your initial visit at our Gastroenterology clinic. If you have already had your screening colonoscopy, ask your provider when you should get another one.


Colon prep takes 1 to 2 days, depending on which type of prep your doctor recommends. Some preps may be taken the evening before the test. For many people, the prep for a colonoscopy is more trying than the actual test. Plan to stay home during your prep time since you will need to use the bathroom often. The colon prep causes loose, frequent stools and diarrhea so that your colon will be empty for the test. The colon prep may be uncomfortable and you may feel hungry on the clear liquid diet. If you need to drink a special solution as part of your prep, be sure to have clear fruit juices or soft drinks to drink after the prep because the solution can taste unpleasant.


Additional Links to patient education:


National Institute of Diabetes and Digestive and Kidney Diseases

American Society for Gastrointestinal Endoscopy

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