Past research shows that colonoscopy is associated with as much as a 69% decrease in new cases of colorectal cancer and an 88% decrease in the risk of death from it.
Like every medical procedure, there are benefits and risks to undergoing a colonoscopy. Fortunately, the benefits greatly outweigh any discomfort you may experience.
The cons: The exam might not detect all small polyps and cancers. A thorough cleansing of the colon is required before the test. Diet changes are needed before the test, and medications may need to be adjusted.
Why do so many people avoid screenings? One of the most common reasons patients avoid colonoscopy is that they don't want to receive bad news. This is understandable, but the majority of patients get positive news after a colonoscopy. Even if we find polyps, they often can be removed before they develop into cancer.
Studies show that, for someone of average risk, the FIT test is a good alternative to colonoscopy. There is also evidence that people unwilling to undergo a colonoscopy will complete a FIT test.
There's no upper age limit for colon cancer screening. But most medical organizations in the United States agree that the benefits of screening decline after age 75 for most people and there's little evidence to support continuing screening after age 85. Discuss colon cancer screening with your health care provider.
Screening Recommendations
The U.S. Preventive Services Task Force (Task Force) recommends that adults age 45 to 75 be screened for colorectal cancer. The Task Force recommends that adults age 76 to 85 talk to their doctor about screening.
Studies estimate the overall risk of complications for routine colonoscopy to be low, about 1.6%. 1 In contrast, the lifetime risk for developing colo-rectal cancer is about 4-5%. 2 To put it into perspective: a person's average risk of developing colon cancer is higher than having a complication after a colonoscopy.
Why it's done. Your doctor may recommend a colonoscopy to: Investigate intestinal signs and symptoms. A colonoscopy can help your doctor explore possible causes of abdominal pain, rectal bleeding, chronic diarrhea and other intestinal problems.
Virtual colonoscopy is a special X-ray examination of the colon using low dose computed tomography (CT). It is a less invasive procedure than a conventional colonoscopy. A radiologist reviews the images from the virtual colonoscopy to look for polyps on the inside of the colon that can sometimes turn into colon cancer.
Advantages: A colonoscopy lets your doctor view your entire colon. If a polyp is found, it can be removed, which may keep the polyp from developing into a dangerous cancer. Disadvantages: You'll need to clean out your bowels with strong laxatives and possibly a special diet a day or more before the test.
If the colonoscopy finds one or two small polyps (5 mm in diameter or smaller), you are considered at relatively low risk. Most people will not have to return for a follow-up colonoscopy for at least five years, and possibly longer.
Comparison of Detection Rates
The multi-targeted stool DNA test is 92% sensitive for finding cancers, which is almost equal to colonoscopy, reportedly at 95%.
In the US, according to data from the US Centers for Disease Control and Prevention, about 1 in 5 adults between the ages of 50 and 75 have never been screened for colorectal cancer.
Flexible sigmoidoscopy
This test is similar to a colonoscopy but only lets the doctor see the rectum and lower part of the colon (sigmoid and descending colon). Before a flexible sigmoidoscopy, you will need to have a light bowel clean-out, usually with an enema.
The tube is inserted into your bottom and goes around the large bowel. The ScotCap Test is a capsule that you swallow, and it contains 2 tiny cameras inside. The cameras take pictures of the lining of the bowel to look for any problems or signs of disease. This test can be used instead of a colonoscopy.
You just let it go like you normally would. However, there are some reasons this option isn't as comprehensive as a colonoscopy. Mail-in stool tests have a 92% sensitivity rate for detecting colon cancer, which is on par with a colonoscopy, but only a 17% sensitivity rate for detecting cancer-causing polyps.
Endoscopy vs Colonoscopy Benefits
There are several reasons a physician may recommend an endoscopy or colonoscopy. While colonoscopy is most commonly performed to screen for colon cancer, endoscopies are usually recommended to investigate problems with the upper intestinal tract.
Thinner and more flexible endoscopes may cause less stretching of the mesentery, which is one of the principal sources of pain during colonoscopy.
A traditional colonoscopy is the most widely known colorectal cancer screening procedure, but many patients are choosing a non-invasive CT (computerized tomography) Colonography instead. A CT Colonography doesn't require sedation and is just as accurate at detecting most precancerous polyps.
Loops or angulation in the colon are possibly the most common patient-related source of difficulty. Some bends require additional skill to navigate. Loops, particularly in the sigmoid colon, can result in loss of control of the endoscope as well as patient discomfort.
As often as 40% of the time, a precancerous polyp — frequently a type called an adenoma — is found during a screening colonoscopy. Colon cancer is found during only in about 40 out of 10,000 screening colonoscopies, Dr. Sand said.