Why Should I Get a Colonoscopy? (Colorectal Cancer)

Colonoscopy exams get a bad rap.

Even though the exam is brief and painless, many people fear and avoid them. Roughly one third of Americans, for whom the exam is recommended, are not getting colonoscopies.

Yet colonoscopy is one of the most effective of all cancer prevention methods. As many as 60 percent of colon cancer deaths could be prevented if everyone 50 years old or above underwent colonoscopies, according to the Centers for Disease Control and Prevention (CDC).

In fact, a study conducted by a team of researchers from Dana-Farber, Brigham and Women’s Hospital, and the Harvard School of Public Health found that those who received either a colonoscopy or a sigmoidoscopy exam – which allows doctors to look inside the large intestine through a thin tube and snip away at precancerous growths – had a markedly lower rate of cancers in the rectum and lower colon than did other patients.

A colonoscopy can detect the presence of colon cancer.
A colonoscopy can detect the presence of colon cancer.

“Colonoscopies are the most sensitive test since they visualize inside the entire colon to screen for the cancer or polyps,” says Jeffrey Meyerhardt, MD, MPH, the clinical director of the Gastrointestinal Cancer Center at Dana-Farber Cancer Institute. “These polyps are precursors for cancer that, if removed, will not turn into cancer.”

Screenings are a test for blood in the stool, repeated annually; an exam with a thin, flexible tube called a sigmoidoscope is usually recommended every five years; for a colonoscopy, every 10 years. According to Meyerhardt, sigmoidoscopies do not require as much prep as colonoscopies, but they are not as comprehensive given that doctors can only see less than half of the entire colon during the procedure.

For most patients, if the exam is normal, a colonoscopy should be repeated every 10 years. If the test detects precancerous polyps or the patient has factors that make him/her higher risk, the physician may recommend that colonoscopies be repeated more frequently.

People at increased or higher risk include those who have a personal history of colorectal cancer or adenomatous polyps (precursors to cancer), a personal history of ulcerative colitis or Crohn’s disease, a family history of colorectal cancers or polyps, or a known inherited hereditary colorectal cancer syndrome (such as familial adenomatous polypsis (FAP) or Lynch syndrome). The age to start screening will depend on several factors and should be discussed with your doctor.

Learn more about the Gastrointestinal Cancer Treatment Center at Dana-Farber.

32 responses to “Why Should I Get a Colonoscopy? (Colorectal Cancer)

  1. Hi, i am only 26 years old however over the past couple years have had hemorrhoids/pain in the colon area. Sometimes even hard to have a bowel movement. I do believe that ive had uncles on my mothers side or.it may have actually been my dad most recently to have had colon cancer. He was in his early 50s. Is this something that i should get checked out or to maybe have an early colonoscopy? Thanks for your time.

  2. Hello, Darren.
    Thanks for your comment. Yes, we’d suggest that you discuss your symptoms with your doctor.
    Best wishes.

  3. Doctor, can you recommend how long I should wait to have a colonoscopy after my last flare up of diverticulitis?

  4. I was diagnosed with colon cancer at age 37. There was mo family hisyory of colon cancer. Had I not had a colonoscopy I may not be here today. All of my siblings had to be screened also. Thankfully they were all fine. The test is painless and you a usually asleep for the entire process. I highly recommend this screening.

  5. I had planned to address this myself, since I feel so strongly about wanting to share the TRUTH about the exam, since there is so much misconception! Dr. Fuchs beat me to it: “COLONOSCOPY EXAMS GET A BAD RAP!” They really do! The prep is no worse than a very few hours of a diarrhea, which we have all had. The exam itself is conducted in a comfortable position, with light sedation, and there is No Pain or Discomfort! I have had two. My husband had no symptoms of colorectal disease, and yet when he became ill he was found to have greatly metastasized colon cancer, and only lived twelve days after his diagnosis. He was only 50, and would have had the recommended exam, but the disease made itself known before he was able to. SCHEDULE THIS TEST WHICH IS ALSO PREVENTATIVE, IN THAT THE PHYSICIAN IS ABLE TO DEAL WITH ANY SYMPTOMS ACTUALLY DURING THE EXAM! ~ The day before my first mammography, 26 years ago at age 40, there was a column, written by a woman, in The Boston Globe. It highlighted the horrible machine, the pain, insult, indignity, and how a “man” designed the machine! I kept my appointment the next day, but I admit to having had the fleeting thought of canceling it. To this very day, I think of woman who perhaps did cancel their mammogram, and what their outcome may have been. And I think of the author of that column who should have approached it in a very different way, explaining and yet ENCOURAGING life saving testing.

    1. Dear Georgia —
      We are so sorry for the loss of your husband. Thank you so much for connecting with us and sharing your experience. Wishing you all the best.

  6. I had a colonoscopy at 50 and they found a very tiny tubular adenoma and because of that I have to go every five years for my colonoscopy. Had I pushed it off who knows what would’ve happened. I was so afraid of the prep. Where I live they let you have a light breakfast the morning before and then it’s clear liquids. The prep was one bottle of MiraLAX mixed in with Gatorade and I had no problems. It wasn’t harsh or anything. When I got to the colonoscopy unit they were so nice and when I was wheeled into the room I was given medicine and all I remember is waking up and it was done. It was easy.

    1. Dear Jane —
      Thank you for connecting with us and sharing your experience with other readers. Wishing you all the best.

  7. A colonoscopy saved my life in 2008. They found an ”area of interest”. Turned out to be squamous cell carcinoma of the anus. My 2nd opinion was @ Dana Farber. I am now about to be 7 years free of cancer. Thank you! I now live a normal and grateful life!

    1. Dear Christina —
      Thank you so much for your kind words and for sharing your experience with us. Wishing you all the best.

  8. I was diagnosed at age 44 – accidentally through a chest x-ray when it was thought I could have pneumonia. My colon cancer had already metastasized (spread) to my lung. No family history. No symptoms. Don’t have time? Think the test will be uncomfortable? Well, the test and prep are not as bad as you probably imagine. And guess what? Caught early, colon cancer can be defeated. Mine was stage 4. Am I frightening you? I hope so – because I don’t want anyone else to go through this! And if you don’t think you have time now….. you WILL regret it later when everyday you spend a good deal of your time combating the disease…. I care, that’s why I want to bring awareness and avoid needless suffering. So please get your colonoscopy if you age 40 or older! My siblings have all been tested. A couple had polps removed during the test. They are fine! I was diagnosed in 2009. And here I am just about 6 years later and living life! Thank you Dana-Farber and Dr. Enzinger! I love the Dana-Farber commercial – “What cancer does not know is you have us.” It is true! 🙂

    1. Dear Meredith —
      Thank you so much for connecting with us and sharing your insight. It’s wonderful to hear you are doing well. Wishing you all the best!

  9. I just had my third colonoscopy. My first and third we performed by the Veteran’s Administration in Jamaica Plain (Boston) and the second at Brigham and Women’s. A one day prep just didn’t seem to work for me…using GoLitely, yuk!. A two day prep with MoviePrep did the trick. I prefer the MoviePrep big time! Never slept through any of the colonoscopies…remained wide awake through all three. Had an adinoma removed (pre-cancerous) this last one so really glad the two-day prep worked. No complications. Although I’m not involved with Dana Farber–thank you for allowing everyone post here. I’m 59 and had my first colonoscopy at 52 second at 58 and last one in March, last month.

    Those of you reading this don’t put it off if you are over 50 and/or have a first-degree family history. My sister-in-law (not genetically related) was 70 when she was diagnosed with Stage 4 colon cancer and we lost her shortly afterward. Just sayin’.

  10. My sisters had been bugging me about getting a colonoscopy for years since our dad had colon cancer but I kept putting it off, mainly because I didn’t have health insurance and I was scared and intimidated by the thought of it, and I didn’t have any problems. So I waited until I had a good job with health insurance, sucked it up and ended up giving in at the age of 53 (just 3 months ago). To my surprise, my doctor told me I had 40+ polyps and that I probably have a rare genetic disease called lynch disease! He immediately referred me to the mayo clinic where I have a wonderful doctor named dr. Riegert-Johnson who has been guiding me through this. I actually have something called afap which is even more rare than lynch and I will need to have my colon removed to prevent me from getting colon cancer which I would almost certainly get if I don’t have it removed. I will be going back for my 3rd colonoscopy in early September to make sure the polyp they removed in my rectum hasn’t grown back so they can leave my rectum (really don’t want that removed) and schedule my surgery. So, I am so grateful I had my colonoscopy and caught this in time before it turned cancerous! Please please have one if someone in your family had colon cancer! It could save your life and they really aren’t bad, just the prep is kinda yucky to drink and you don’t really have diarrhea like I thought (upset tummy and stuff). Just think of it as draining your plumbing, same concept! And you sleep right through the procedure. Piece of cake! Go do it.

  11. I just had my second upon turning 60, and had a small polyp removed. The sedation really isn’t necessary. I’ve had both mine without and have had no pain, just mild discomfort. I understand that the doctors would have a hard time doing them with folks writhing around but that doesn’t have to be the case. In Europe the vast majority are done without any sedation. The alleged need for it increases cost, discourage people from doing it because of the need for a driver, and supports the false conception that it is a difficult painful procedure, which it isn’t. And the people who have them don’t even know that, because they can’t remember it, or think it was the drugs that made it easy.

  12. I’m meant to get one every two years now because I have a past history of Chrones(in remission and not on any meds). Since I have a history it isn’t considered preventative and I have to pay 100% of the cost. I am a 25 year, full time employee of our town, which recently switched everyone to a high deductible. I never thought I’d have to forgo recommended tests but I simply can not afford that cost on top of the cost of our insurance. Welcome to the ugly truth.

  13. If you are passing some blood, don’t let your doctor tell you it is internal hemorrhoids, my doctor told me that and said not to worry, so I went years not6 worrying, many years. I now have stage four colon Cancer had part of my colon removed along with 40% of my Liver and a few other things. GET the colonoscopy it is so simple and no big deal,

  14. My biggest hang up about getting one is the prep for it. I’ve heard the product you have to drink and the amount is awful (tasting and a lot)! If they could make a pill that would clean you out I’d be all for that.

  15. It’s not so bad. I had movie prep and after each cup I would drink a chaser of Gatorade. I had my first colonoscopy last year at age 65. No polyps just some internal hemorrhoids. So get the test. It’s not so bad before. Just a case of diarrhea which everyone gets once in a while. My mom died of breast cancer diagnosed at stage 4. She had insurance and was getting checkups regularly but failed to get the important one the mammography. So I’m being vigilant as much as I can.

  16. I thought new technology came out that you did not have to drink and go through the prep

  17. Can’t afford it. I have “insurance” which doesn’t kick in until I’ve put out $5000. So I’ll hope for the best.

  18. Never understood the reasoning that someone would forego having a potentially life saving preventative screening, due to the distaste or discomfort of the preparation. Waiting can often lead to significantly greater discomfort and mental anguish if cancer or other serious maladies are discovered. Fear never changed a diagnosis.

  19. I had my first colonoscopy at age 23 where they found a benign polyp. Since then, I have had 4 more colonoscopies (1 every 5 years) that were normal with no polyps. I am now 53 and am wondering that since I have had no polyps for 30 years, do I still need to go in every 5 years or can I switch to going in every 10 years?

  20. Dear Becky,

    Thank you for your comment. As every individual and his or her medical history is different, we recommend you speak with your doctor about what the most appropriate screening schedule is for you.

    We wish you the best.

Comments are closed.