The Frontal Cortex

Making Colonoscopies Less Painful

Good news: cancer deaths have declined for the second year in a row. This trend has a number of causes, including fewer smokers and improved treatment options. But one cancer accounts for more than 65 percent of the overall decline in deaths:

By far the greatest decreases in mortality have been in colorectal cancer — 1,110 fewer deaths in men, 1,094 fewer in women.

Dr. Elizabeth Ward, a managing director in epidemiology and surveillance at the cancer society, said the most important factor in the decrease was screening for colorectal cancer, which can detect the disease early when it is most treatable, or even prevent it entirely by finding precancerous polyps, which can be removed before they turn malignant. Progress has been significant even though only about half the adults who should be screened have been. If more people were screened, there would be even steeper declines in death and the incidence of the disease.

So how can we get more people to undergo preventative screening for colon cancer? The main method of screening is a colonoscopy. During a colonoscopy, a small camera mounted on a flexible metal tube is inserted into the large intestine. As you might expect, the procedure is rather painful, and normally lasts about 45 minutes. Many patients don’t return for a follow up colonoscopy precisely because the procedure is so uncomfortable.

So how can we make colonoscopies less painful? In the mid-1990′s, the psychologists Donald Redelmeier and Daniel Kahneman came up with a brilliant method. They studied two groups of patients undergoing colonscopies. One group received a standard colonoscopy. The second group received the same treatment, except that at the very end of the procedure the doctors let the instrument sit in place for a few extra minutes. (This is relatively painless, at least when compared to the probing that comes before.)

Which group experienced less pain? At first glance, the answer seems obvious: the first group would report less overall pain, since their procedure was a few minutes shorter. But this isn’t what happened. The second group experienced significantly less discomfort. Of course, this is a completely counterintuitive reaction, since it implies that the way to make a medical procedure less painful is to make it last longer. According to Kahneman, the only trick is to make the additional minutes represent a relative decrease in the intensity of pain. When doctors listened to Kahneman’s advice, patients were more likely to return for a follow-up colonoscopy.

How did the psychologists explain this counter-intuitive result? According to Kahneman, people judge their sensory experience relative to a reference point, which in this case was the painful sensation of a camera probing their intestine. As a result, when the probe stopped moving, what the subjects perceived was a relative decrease in pain, which felt nice. The happy ending made up for the overall increase in painful moments. (This is known was the peak-end rule.) As Kahneman observes, “A general property of perceptual systems is that they are designed to enhance the accessibility of changes and differences. All perception is reference-dependent.”

PS: I’ve been asked why I spend so much time talking about prospect theory and Kahneman and Tversky. The main reason is that I find their research fascinating and full of relevance to the real world. The other reason is that Kahneman and Tversky play a significant part in my next book (I’m still in research mode).

Comments

  1. #1 Kevin W. Parker
    January 18, 2007

    I’m getting a colonoscopy next week, and the doctor said that I would be unconscious during it. The only part I’m dreading is the 24+ hours of fasting and clearing the system out I have to go through beforehand.

  2. #2 Rugosa
    January 18, 2007

    When I had a colonoscopy, it was under mild sedation. No pain at all, and I was able to watch it on the monitor – fascinating! It was much less uncomfortable than a mammogram.

  3. #3 Eric Juve
    January 18, 2007

    When I had my first colonoscopy, it was under sonombulastic anesthesia ( I think thats what they called it ), I didn’t remember a thing. My doctor only works in a hospital that is 1 1/2 hours from here now and of course one can’t drive for 24 hours after the procedure. I asked if they would do it without the anesthesia and was informed that they felt it would be malpractice to subject patients to that much pain, not discomfort, PAIN.

  4. #4 J-Dog
    January 18, 2007

    If I have it done, I will go Eric’s route, no pun intended…

  5. #5 Sam
    January 18, 2007

    My doctor told me that I could have an IV sedative, or nothing. He said most people who didn’t recieve any anesthesia found the procedure uncomfortable but tolerable. I opted for no anesthesia. It was painful, but I appreciated being given the option, and would probably opt for no anesthesia on my return visit. Perhaps I’ll ask him about this experiment next time!

  6. #6 Mark P
    January 18, 2007

    My experience was like Eric’s. I felt nothing and remember nothing. For me, and I suspect many others, the biggest obstacle is drinking about five gallons of foul-tasting liquid intended to completely clear out the intestines. That is something I dread.

  7. #7 Babs
    January 20, 2007

    I had a colonoscopy on Monday, 1-15. It was the most painful event I ever experienced. I was actually wailing out loud and begging the doctor to stop, and I have almost none of the amnesia that was promised. The hospital is investigating this case … there is a suspicion that this particular physician is either undersedating or starting the proceedure before sedation takes effect just to bolster his desire to use propanol, a much stronger drug that the hospital refuses unless an anesthesiaolgist is present. The gastroenterologist feels he can administer the drug himself. My complaint against him is the 5th one on recent months. What a monster!

  8. #8 Tim
    January 26, 2008

    I had a similar experience. It felt as though they were shoving a 50 caliber shell through me throughout the procedure. I beat on the rail of the bed and begged him to stop and his sole reply was no! I feel as though I was raped! I’ve had two kidney stones and were it not for duration, I’d rather have those. Interesting comment about your theory he may not be waiting long enough for the sedative to take effect. The nurse barely got the syringe out of my IV before he inserted the tube. And by the way, they told me I got Versed and Fentanyl, yet I only recieved one injection before commencing. When I confronted the hospital, they indicated I was given a double dose of both, the second dose coming 11 minutes into the procedure. Will I get another one???, have no choice. Do I believe what I read about painless procedure??? yes, I do. It’s the most frustrating thing about it. It’s like no one believes you. All hospital staff says ‘hey, we do many of these and the patients experience no pain, if they even remember the procedure at all and that’s with half the pain medication we gave you’. This prompted an obvious question from me…”why did you give me the second dose”? Someone’s lying, but what am I to do? I believe my next experience will be better, given all I’ve read about the procedure and sedation. In the meantime, my only recourse is to tell everyone I know to avoid this particular doctor and hospital.

  9. #9 Chuck
    December 2, 2008

    I just had a colonoscopy yesterday. The nurse inserted my iv, then injected some saline, I put my gown on, was wheeled into the procedure room, quickly got an O2 and blood pressure pulse monitor put on, the gastroenterologist arrived, gave me a shot of proponol, and another of versed, then I don’t remember much other than looking at the screen. (I have a vague memory of looking at the inside of my colon, but it was painless.) My neighbor drove me home, and I made him stop at McDonalds so I could get a burger to get rid of the hunger pangs. Mine was a “walk in the park”.

  10. #10 Morticia
    May 13, 2009

    I had a colonoscopy recently and it was the most horrible, painful experience of my life. I was given demerol and versed and told I would not be aware of what was going on but I remember everything the Dr and nurses were talking about and even what radio station they had on. That is, when I could hear above my screaming and begging them to stop or give me more meds. I will never have one again. I was hoping for death during that procedure and now am having nightmares.

  11. #11 Judy
    July 8, 2009

    I am a 46 yr old female who had my first colonoscopy last year. After much research, I decided to go with NO sedation. The US is the only country in which sedation is given “automatically.” I decided that between childbirth, menstrual cramps, and a toothache, there couldn’t really be anything more painful, and in my opinion I was right, not to mention the digestive pain I get when I consume hot wings and blue cheese.
    Upon admission, I informed the staff that I did not want sedation, and they were shocked, it was almost unheard of. I asked the Dr if he were having the procedure if he would be sedated and he said probably not. They put the IV in just so they could have access if I changed my mind.

    Let me tell you, yes there was some mild discomfort especially when the blew the air in, and of course my colon wasn’t happy to have an invader going “the wrong direction” but there was NO PAIN. He removed two polyps. I watched the whole procedure and got to take home the pictures as well.

    A colonoscopy is not painful, and really no big deal. If you have ever eaten something and felt your stomach start to rumble or had a belly full of gas, then you can handle a colonoscopy. It only takes about 30 minutes, and is life saving.
    My fiancee just had the procedure today with no sedation and when asked if he would choose sedation next time, he replied, “Now that I have experienced it and know what to expect, it will just depend on how I feel, like choosing to take an elevator or the stairs.”

    Don’t let these people scare you. Four of my friends have now skipped the sedation, they drove away from the hospital, didn’t have the awful side effects of the drugs.

    Whether you choose sedation or not, just have one done. I challenge you to skip the sedation.

  12. #12 Liz
    May 30, 2010

    I have had two colonoscopies in the past and they were very different. I remembered every minute of the first one.They started an IV but I’m convinced they forgot to open the stopcock & run the sedative in because I was fully awake and aware of the pain the entire time.Immediately after I left the hospital with my husband, we stopped to have breakfast,then did some shopping,and I went home and put up the Christmas tree. Does that sound like someone who had just been sedated a short time before ? When the bill came I called the hospital to contest the charges for medication,but because it was documented in my record,it was my word against theirs & they refused to adjust the bill.