Screening Colonoscopy

A screening colonoscopy looks for polyps or cancer in someone with no symptoms. Most screening tests like PAP smears, mammograms and PSA are designed to find cancer early. A colonoscopy goes one better and can prevent you from ever getting colorectal cancer. Many insurance companies will pay for the entire cost of the procedure without copays or deductibles.

When Should I Get a Screening Colonoscopy?

The recommendations to start screening for colon and rectal cancer are:

  • If a person has never had colorectal cancer or polyps and has no relatives with cancer or polyp then age 50
  • If a first-degree relative (parent, sibling or child) had cancer or polyps diagnosed after age 60 or 2 second-degree relatives have had colorectal cancer then age 40
  • If a first-degree relative was diagnosed with cancer or polyps at or before age 60 or 2 first degree relatives at any age then age 40 or 10 years before the youngest affected relative whichever is first
  • If a person has a history of multiple family members with cancer even of different kinds of cancer, they should talk with their doctor about genetic testing as they may need to start screening as early as age 20 or even younger in special circumstances.

Procedure Preparation

If your doctor orders a screening colonoscopy, he will ask you to clean out your colon. To do this, you may be asked to follow a special diet and take a laxative the day before the exam and possibly take a laxative the day of the examination as well. The doctor will need to know ahead of time which medicines you are taking so he can take precautions accordingly. You may be asked to stop taking some medicines temporarily or to possibly adjust the dosages. 

During the Procedure 

The procedure usually lasts about 20 to 30 minutes. Prior to the procedure, you should expect a sedative either in pill form or through an IV to minimize any pain. The doctor will insert the colonoscope into your rectum while you are lying on your side on the table with your knees pulled up to your chest. 

While the colonoscope is inside your colon, the doctor will pump air through the tube into your colon. This widens the colon to give the doctor a better view. During this procedure, you may feel cramping or the urge to make a bowel movement.

The camera on the colonoscope lets the doctor see the inside of your colon as it is moving through. If the doctor sees anything out of the ordinary, he will ask you to come back for a diagnostic colonoscopy. 

After the Procedure 

When the procedure is complete, you will need at least an hour to recover from the sedative and will need a ride home. The sedative may take a full 24 hours to wear off. Do not expect to be able to drive home or return to work until at least the next morning.

The air that was pumped into your colon during the procedure may cause bloating or may cause you to pass gas later. If this happens, walking will help to ease any discomfort.

If you notice a small amount of blood in your first stool following the exam, just let your doctor know, especially if you continue to pass blood or have blood clots.

What are the Results?

If the test is normal, it may only need to be repeated every 10 years, depending on your risk factors. 

If you get a positive result, it means the doctor found some abnormalities such as polyps or abnormal tissue. If this happens the doctor will order a diagnostic colonoscopy to remove any polyps they find to be sent to the lab for a biopsy. Some polyps can be cancerous or precancerous, but most are not. 


A screening colonoscopy is performed on someone who has reached a certain age. If the results are abnormal, a diagnostic colonoscopy will be ordered. It is the same test but it is done for a specific reason such as bleeding, pain, a change in bowel habits, diarrhea, or constipation. These are present symptoms that make us want to look at the colon as a potential problem. If surgery is required, the professionals at Nevada Surgery & Cancer Center in Las Vegas can help.