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Colonoscopy and Colorectal Screening

A colonoscopy is a common outpatient procedure that examines the colon and rectum using a long, flexible instrument called a colonoscope. During the procedure, we look for numerous things, including polyps, cancer, inflammation, diverticulosis, and blood vessel abnormalities in the bowel lining. We can also take biopsies and remove polyps to help diagnose disease and prevent people from developing cancer.

Below is more in-depth information regarding the various tests and procedures associated with colorectal cancer screening.

  • Who should have a colonoscopy
  • What preparation is required for getting a colonoscopy?

Prior to getting a colonoscopy, it is very important that the colon be thoroughly cleansed and emptied. This is done by taking a bowel cleansing drink (also known as a “bowel prep”) that is prescribed by your doctor. You must follow the instructions provided to you carefully to insure that the colon is as clean as possible.  Most often, people start taking the preparation the day prior to the procedure and also only drink clear liquids that day.

Inadequate preparation may prevent the performing doctor from having the clearest view during the procedure. This could result in the colonoscopy needing to be repeated at a different time.

Click on the links below to view our detailed preparation instructions which vary slightly depending on what part of the day you are scheduled for your colonscopy.

How is a colonoscopy performed?

A colonoscopy usually takes about 30 to 45 minutes and is performed in an outpatient unit following a thorough bowel cleansing. Routinely, patients receive sedation through an IV during the procedure. An instrument called a colonoscope is passed through the rectum (last 6 inches of the bowel) up to the beginning of the colon to look for any abnormalities. If there is anything found, it may be biopsied or removed. 

For some patients, we will only recommend a more limited procedure called a flexible sigmoidoscopy. In that procedure, we typically only examine the last half of the colon.

What are the risks associated with having a colonoscopy?

First and foremost, it is important to understand that most of the time, the benefits from getting a colonoscopy far exceed any risk. If someone can have a cancer prevented or have a cancer identified before it spreads, a patient’s life can be saved. However, there are some risks associated with the procedure. The most common problem after colonoscopy is cramping related to the gas that is used to inflate the bowel for the procedure. This is a temporary issue that goes away relatively quickly. Other problems are much less common, but can be more serious. These include bleeding, perforation (rupture) of the colon requiring urgent surgery, inability to complete a full colonoscopy, and reversible oversedation.

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