Colon cancer is the second leading cause of cancer death after lung cancer. In an otherwise healthy, non-smoking population, colon cancer is the number one cancer killer. Elgin County has a higher prevalence of this disease than the provincial average.  It is also known as bowel cancer as the colon is another name for the large bowel.

This silent killer most commonly presents in one of three ways. It can cause progressive, barely perceptible anemia due to loss of microscopic quantities of blood in the stool. It can present with obvious rectal bleeding which is often wrongfully attributed to much less serious problems such as hemorrhoids. Colon cancer can also present with a change in bowel habit characterized by either increasing constipation or intermittent diarrhea. All of these symptoms are very vague and generalized and have the ability to “fool” the patient into thinking that nothing serious is going on.  On a positive note, long before a patient has symptoms from a colon cancer, there is often a clue that a cancer may develop.  This is because colon cancer usually develops from a small growth, or polyp, that takes years to develop into cancer.  A polyp can present with bleeding but often has no symptoms at all. 

In the war against colon cancer, the most effective tool is screening colonoscopy as it can find and remove polyps before them become cancers.  The colonoscope is a flexible, fiberoptic camera at the end of a narrow tube that is four feet long.  It is used to visualize the rectum and large bowel (colon).  The doctor performing the procedure skillfully guides the instrument using directional controls built into the eyepiece.  Patients are generally sedated with medication and most patients feel no pain and have no recollection of the test, due to the nature of the medications used.

Of all the cancer screening tests, colonoscopy is somewhat unique as it can diagnose a precursor to the cancer and therefore prevent the patient from actually getting the cancer for which it is screening. Patients with rectal bleeding and those with a family history of colon cancer make up a large portion of those patients who undergo colonoscopy.  By removing a polyp from the colon before it turns into cancer, the endoscopist can save lives everyday.    

Robert T. Black MD, FRCSC, FACS
General Surgeon
Chief of Surgery
St. Thomas Elgin General Hospital
Academic Director of Community Surgery, Schulich School of Medicine
Adjunct Professor of Surgery
University of Western Ontario