Colorectal cancer is the second most common cause of cancer death in the US. There are effective screening techniques available that can greatly decrease an individual’s chances of dying of this disease. Although colonoscopy is commonly recommended to screen for colorectal cancer for people in certain age groups, this procedure can be uncomfortable, leading many people to look for an alternative.
Is there an alternative to a colonoscopy? Is an “at home colonoscopy” test effective at catching colorectal cancer?
How does a colonoscopy work?
For a colonoscopy, a doctor inflates the colon with gas, and inserts an instrument called a scope through the anus. This has a camera and a light on the end, allowing the doctor to view the inside of the rectum and colon. The scope also allows the doctor to use specially designed surgical instruments to remove any concerning pieces of tissue.
Colorectal cancer is a slowly growing type of cancer. It generally starts as a bump of tissue called a polyp, and this develops into cancer over a period of several years. During a colonoscopy, the doctor can remove any concerning polyps, preventing cancer from occurring. As a result, a colonoscopy is not only a method of detecting cancer, but also a method of preventing it.
However, colonoscopies can be uncomfortable. You receive a sedative medication during the procedure itself, and most people don’t even remember it. The prep beforehand is the part that most people dread – your colon needs to be cleaned out for the procedure, so you need to take medications that induce diarrhea in order to ensure that your colon is empty. Unfortunately, some people dread having a colonoscopy so much that they avoid the procedure. They would rather have an alternative to colonoscopy screening.
Is there a colon cancer home screening method?
Fecal immunochemical testing, or FIT, is another method that’s used to screen for colorectal cancer, making it a potential substitute for colonoscopy. This test looks for signs of blood in the stool. Earlier versions of this test simply looked for the presence of blood, but eating meat could potentially cause a false positive on the test, because the blood from the animal would show up on the test. This required people to change their diets before doing the test. The modern FIT test looks specifically for human blood in the stool, so you don’t have to change your diet before having it.
Is FIT a good alternative to colonoscopy?
FIT looks for the presence of blood in the stool. This means that the test can only detect a cancer or a polyp if it’s bleeding. Colorectal cancers usually bleed, causing them to show up on the test. However, polyps don’t always bleed, and the “colonoscopy home test” can miss these.
Studies have shown that FIT detects nearly all cases of colorectal cancer. However, it misses about half of precancerous polyps. Because people are more likely to take a “mail in colonoscopy” test than to go in for a full colonoscopy, FIT is still considered to be a good screening method, even though it can miss some precancerous polyps.
You’re eligible to consider FIT instead of colonoscopy if you’re of average risk for colorectal cancer (meaning that you don’t have a strong family history of this disease). If you’re at higher risk due to your family history or other factors, then colonoscopy instead of FIT is recommended for you.
How can you get an “at home colonoscopy” kit?
If you’re using FIT as your colorectal cancer screening method, doctors recommend that you do the test every year, from ages 45 to 75. You simply order the kit online through a home testing service. The colonoscopy alternative comes straight to your home. There will be instructions for collecting a stool sample in the privacy of your own home. Then you mail the sample to the laboratory, where it will be tested. You get your results online within a few days.
If you get a positive result on FIT (meaning that blood is detected), then you’ll need a colonoscopy to follow up. A colonoscopy is the only way to determine what’s causing your bleeding, and to biopsy or remove any concerning polyps or possible cancers that are found. This means that having FIT doesn’t guarantee that you won’t need a colonoscopy. However, it might allow you to avoid a colonoscopy, because if the test is negative (meaning that no blood is found), then you won’t need to have the procedure.
An Update on Cancer Deaths in the United States. Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/dcpc/research/update-on-cancer-deaths/index.htm. Accessed 25 August 2022.
Colorectal Cancer Screening Tests. American Cancer Society. https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html. Accessed 25 August 2022.
Is Home Screening a True Colonoscopy Alternative? Yale Medicine. https://www.yalemedicine.org/news/colon-cancer-home-test. Accessed 25 August 2022.
Quintero E, Castells A, et al. Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. N Engl J Med. 2012 Feb 23;366(8):697-706. doi: 10.1056/NEJMoa1108895.
US Preventive Services Task Force. Screening for Colorectal Cancer – US Preventive Services Task Force Recommendation Statement. https://jamanetwork.com/journals/jama/fullarticle/2779985. Accessed 25 August 2022.