Colorectal cancer begins in either the colon or the rectum. Colorectal cancers generally develop slowly over a period of several years.  There are often earlier changes in the lining of the colon or rectum before a true cancer develops.  A polyp is growth of tissue that makes up one type of these changes.   Early removal of a polyp may help prevent it from becoming cancer.  Adenocarcinomas account for over 95 in 100 of colorectal cancers.

Approximately 90 out of 100 individuals who have colorectal cancer are older than 50 years of age. Therefore, it can be said that age is a risk factor for developing colorectal cancer.  Signs and symptoms of colorectal cancer may include rectal bleeding, blood in the stool, and a change in bowel habits.  Other options for colorectal cancer screening include a fecal occult blood test, flexible sigmoidoscopy and double contrast barium enema.  It is felt that if one of these screening tests for colorectal cancer is positive, then it should be followed up with a colonoscopy.

Prior to a colonoscopy, the colon is cleaned out through the use of laxatives and an enema.  This cleansing of the colon removes any stool that may block the view during the procedure.  A colonoscopy is usually done in a hospital outpatient department and takes approximately 30-45 minutes.  Medication is usually given through a vein during the procedure to help avoid discomfort.  A colonoscopy is an invasive procedure.  It is performed by inserting a long, flexible fiberoptic-viewing instrument called a colonoscope through the rectum up into the colon.  The instrument reaches the cecum 95 in 100 of the times it is performed.  During the procedure, the colonoscope is connected to a video camera and video display monitor.  This allows the physician to closely examine the inside of the colon.  Both polyp removal and tissue samples (biopsies) can be performed during a colonoscopy.

• There were an estimated 148,810 new cases and 49,960 deaths from colorectal cancer in 2008 in the United States.
• The lifetime risk for an individual to develop colorectal cancer in the United States is nearly 6 in 100, with over 90 in 100 cases occurring after age 50 years.
• Colonoscopy is an effective colorectal cancer screening for individuals age 50 years and older.
• The American Medical Association (AMA) and collaborating professional organizations support the use of colonoscopy as a colorectal cancer screening every 10 years for individuals age 50 years and older who have no other risk factor but age.
• The American Society for Gastrointestinal Endoscopy (ASGE) states, “indirect evidence suggests that most cancers develop from adenomatous polyps and that it takes an average of 10 years for a less than 1cm (less than 1/4^th of an inch) polyp to transform into invasive colorectal cancer.”

Will I live longer if I have a screening colonoscopy?

This procedure may lengthen your life by early detection of colorectal cancer.  It may also prevent colorectal cancer by finding and removing polyps that might have become cancer. 

Will having a screening colonoscopy improve my quality of life?

This procedure may lead to early colorectal cancer detection, treatment or prevention that may improve the quality of your life. 

Does a colonoscopy identify colorectal cancer earlier than not having the procedure?

A colonoscopy can detect colorectal cancer when used as a screening tool.  It offers the most thorough look at the entire colon.

How safe is this for me?

How safe is a colonoscopy for me?

This procedure is invasive.  There is the possibility of complications from the colonoscopy procedure.

Minor reported complications:

• Pain and discomfort associated with the procedure
• Discomfort with bloating or pain following the procedure
• Bleeding after the procedure
• An allergic reaction to the medication used for sedation

Major reported complications:

• Approximately one out of every 1,000 people having this test done may sustain a tear in the wall of their intestine which might require surgery to repair
• Bleeding after the procedure
• An allergic reaction to the medication used for sedation

Other procedures for colorectal cancer screening include:

• Double contrast barium enema
• Flexible sigmoidoscopy
• Fecal occult blood test

It is felt that if one of these screening tests for colorectal cancer is positive, then it should be followed up with a colonoscopy.

Evidence based quality studies have not been done to compare which screening test for colorectal cancer is the most accurate/cost effective. Colonoscopy offers the most thorough look at the entire colon.  It is felt that if one of the other screening tests for colorectal cancer (double contrast barium enema, flexible sigmoidoscopy or fecal occult blood) is positive, then it should be followed up with a colonoscopy.  Earlier detection and treatment of colorectal cancer may lead to a better treatment outcome and longer life.

The cost may or may not be covered by your health benefits plan.

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