A Colonoscopy enables a physician (usually a gastroenterologist) to directly image and examine the entire colon. It is effective in the diagnosis and/or evaluation of various GI disorders (e.g. colon polyps, colon cancer, diverticulosis, inflammatory bowel disease, bleeding, change in bowel habits, abdominal pain, obstruction and abnormal x-rays or CT scans) as well as in providing therapy (for example, removal of polyps or control of bleeding). It is also used for screening for colon cancer. A key advantage of this technique is that it allows both imaging of abnormal findings and also therapy or removal of these lesions during the same examination. This procedure is particularly helpful for identification and removal of precancerous polyps.

What is a colonoscope?

A colonoscope is a flexible and steerable instrument to evaluate the entire colon (large intestine). The large intestine is approximately 3 – 4 feet long. A colonoscope is engineered such that biopsies of suspicious areas can be obtained, and polyps (which may turn into cancer) can be removed.

Has colonoscopy been shown to be effective in preventing cancer of the colon and saving lives?

Yes. Colonoscopy accomplishes this by detecting and removing polyps, and detecting early cancers. Recent data show that both the number of new cases of colon cancer (incidence) and deaths from the disease are decreased when colonoscopy is performed according to established guidelines.

If colonoscopy is so effective at detecting polyps, colon cancer and saving lives, why aren’t more people having it?

The most common reason patients cite for not getting a colonoscopy is that their doctor did not discuss it with them. The next most common reason is fear or avoidance of the preparation (“prep”), which involves taking a laxative which causes temporary diarrhea for several hours. In addition, many people are simply unaware that they need colon cancer screening.

Is colonoscopy painful? Will I be sedated?

No, colonoscopy is usually not painful! Almost all colonoscopies can be performed using “intravenous sedation” or “twilight sedation” in which you are very drowsy, but comfortable and still breathing on your own. The most common type of sedation also has a mild amnesiac effect, so most patients do not even remember the procedure! Your doctor can discuss with you the best form of sedation to suit your needs.

Colorectal Cancer (CRC) Risk Factors

What is my risk of developing colon cancer if I live in the United States?

Your lifetime risk (defined as life to 85 years old) is approximately 6% (male or female). Your risk is roughly doubled if one (1) first degree relative (parent, sibling or child) had colon cancer or polyps after age 50, and is higher if the cancer or polyps were diagnosed at a younger age or if more members of your family are affected. Certain inherited disorders, for example, polyposis syndromes and hereditary non-polyposis colorectal cancer, can increase your risk of developing colon cancer, but those are rare. Other important risk factors include obesity, cigarette smoking, inflammatory conditions in the colon such as Crohn’s, Colitis and Ulcerative Colitis, red meat consumption, and excessive alcohol consumption. Your doctor is in the best position to discuss whether your personal or family history suggests one of those conditions.

When should I have a colonoscopy? If you have no colorectal symptoms, family history of colon cancer, polyps or inflammatory bowel disease you should have your first exam at age 45 whether you are a man or a woman since colon cancer affects both EQUALLY!If one or more first degree relative (parent, sibling or child) has had a precancerous polyp or colon cancer, the general guideline is to begin colon cancer screening 10 years younger than the youngest age of the family member with colon cancer, or age 40, whichever is younger. There are additional guidelines for suspected or confirmed rare syndromes, and you should discuss these options with your doctor.

Alternative Screening

Are there other methods to examine my colon besides colonoscopy?

Yes, there are alternative methods to examine the colon, but none are considered more accurate at colon cancer and polyp detection than colonoscopy. They include:

• A flexible sigmoidoscopy

  
  

• Computerized tomography (CT), a test that takes pictures of the inside of the colon, can also be done. This is called CT colography or “virtual colonoscopy.” Like conventional colonoscopy, this test requires a full preparation the day before the exam (liquids and possibly enemas). This test, however, involves radiation exposure which may increase your long term risk of development of cancer.

  
  

• If any of the above tests suggest the presence of polyps or cancer, a conventional colonoscopy (and a second preparation) will be required. For colon cancer screening, it should be noted that colonoscopy has the highest sensitivity and is the only test that is both diagnostic and therapeutic.

Bowel Prep

Please refer to instructions that Digestive Disease Specialists has given you.

Complications

Potential complications are associated with virtually every form of testing done in medicine. Clearly, colonoscopy has been found to be extremely safe when performed by a well trained physician such as a gastroenterologist. Although quite rare, most complications are related to sedation administration (cardiac and respiratory problems); the colon may also become partially torn (perforated) and this may require surgery. Rarely, bleeding from polyp removal or from the procedure itself may require additional treatment such as hospitalization and/or blood transfusions. As one reads about these procedures, the reader should weigh these low risks against the far more frequent complication of developing colon cancer if appropriate testing is NOT done.

https://gi.org/topics/colonoscopy/