What do colonoscopies check for

Colon cancer is among the most common — and preventable — cancers: about , people are diagnosed with colon cancer each year in the US and more than 50, people die of the disease annually. This makes it the 2 nd leading cause of cancer-related death in the US. So, you should be familiar with colonoscopy if you aren't already. That's the test during which a doctor places a flexible tube through the rectum into the colon to look for polyps, tumors or other problems.

As awful as it may sound, it's usually well-tolerated: you're sedated for the procedure and often people don't even remember having it. We're lucky to have such a good screening test for colon cancer - colonoscopy can not only detect tumors while they're curable, but it can identify precancerous polyps which can be removed before they become cancerous. For people at average risk of colon cancer, colonoscopy is usually recommended as a screening test at age 50 or age 45, according to the American Cancer Society.

It should be repeated every 10 years thereafter until age It is often recommended for younger people or more frequently for those who notice blood in their stool, have unexplained anemia or a change in bowel habits, have a strong family history of colon cancer or other risk factors for the disease.

While the test does come with some risks such as pain, bleeding or even perforation , serious complications are quite rare. Much is written about "the prep" for colonoscopy to clean out the colon so that its interior can be clearly viewed and the procedure itself , but less is written about what the results may mean. As a screening test, it's usually done to find colon cancer or precancerous polyps. But, often neither is found; instead, other, potentially confusing or surprising findings may be discovered.

While small polyps can often be removed during colonoscopy, larger ones may require surgery. Risk factors for colon polyps are similar to those for colon cancer, including advanced age, family history of polyps or cancer, a diet high in red meat, or a history of inflammatory bowel disease. Other, less common findings include a "foreign body" such as when a child swallows a toy or a fistula an abnormal connection between the colon and another part of the intestinal tract or other organ.

Some of the findings of a colonoscopy are known right away. If they can affect your colonoscopy, your doctor may tell you to stop taking them. These might include:. Your doctor may give you a laxative to take the night before your appointment. You may want to arrange for a ride home after your appointment.

Most people get a sedative and pain medication through an intravenous line. Your doctor may position you with your knees close to your chest to get a better angle to your colon.

A camera on the end of the colonoscope transmits images to a monitor that your doctor will be watching. Once the colonoscope is positioned, your doctor will inflate your colon using carbon dioxide. This gives them a better view. Your doctor may remove polyps or a tissue sample for biopsy during this procedure.

The entire procedure takes 15 minutes to an hour. Give this time to get out of your system. Also, a little bit of blood in your stool after the procedure is normal. However, call your doctor if you:. Virtual colonoscopy uses a CT scan or MRI to take images of your large intestine from outside your body. Learn how it compares to a traditional…. Talk with your doctor about what colon cancer screening option is best for you.

Together, you can decide based on your overall health when screening may no longer be of benefit. Michael F. Picco, M. There is a problem with information submitted for this request.

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You may opt-out of e-mail communications at any time by clicking on the Unsubscribe link in the e-mail. Our Housecall e-newsletter will keep you up-to-date on the latest health information. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. Any use of this site constitutes your agreement to the Terms and Conditions and Privacy Policy linked below. Most polyps aren't cancerous, but some can be precancerous.

Polyps removed during colonoscopy are sent to a laboratory for analysis to determine whether they are cancerous, precancerous or noncancerous. Depending on the size and number of polyps, you may need to follow a more rigorous surveillance schedule in the future to look for more polyps. If your doctor finds one or two polyps less than 0. If you have a polyp or other abnormal tissue that couldn't be removed during the colonoscopy, your doctor may recommend a repeat exam with a gastroenterologist who has special expertise in removing large polyps, or surgery.

If your doctor is concerned about the quality of the view through the scope, he or she may recommend a repeat colonoscopy or a shorter time until your next colonoscopy. If your doctor wasn't able to advance the scope through your entire colon, a barium enema or virtual colonoscopy may be recommended to examine the rest of your colon. Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions. Mayo Clinic does not endorse companies or products.

Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Overview Colonoscopy Open pop-up dialog box Close. Colonoscopy During a colonoscopy, the doctor inserts a colonoscope into your rectum to check for abnormalities in your entire colon.

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