Skip to main content Skip to secondary navigation

Extending a Procedure Can Make It Less Painful

Main content start
A doctor shakes hands with a patient


Colonoscopies can prevent colon cancer, yet the painfulness of the procedure deters patients from screening.


Prolonging the painless final moments of a colonoscopy leads patients to recall the entire procedure as less painful, which in turn increases their willingness to undergo more screenings in the future.

The Details

Medical doctor Donald Redelmeier and his colleagues randomly assigned colonoscopy patients into one of two groups. The control group received a standard colonoscopy screening, while the treatment group received three extra minutes of procedure, during which the scope painlessly rested on the tip of the rectum. Following the colonoscopy, patients rated the painfulness of the procedure as a whole.

The researchers found that patients in the treatment group rated the overall colonoscopy as 10% less painful than did patients in the control group. Patients in the treatment group were also 18% more likely to make a return visit.

Why This Works

Our memories of how painful an event was do not not necessarily reflect how long the pain lasted. Instead, the biggest drivers of our recollections of pain are the intensity of the sharpest pain and the last moments of pain before the event ends. And so reducing the pain at the end of a colonoscopy can change people’s memories of how painful the entire procedure was.  

When This Works Best

Because sharp pain increases people’s recollections of how painful an event was, this intervention works best when the pain is steady and without intense peaks. 

The Original Study

Redelmeier et al (2003). Memories of colonoscopy: A randomized trial. Pain, Volume 104 (Issues 1–2), pp. 187-194. 

In the Press

TED 2010: The Riddle of Experience vs. Memory

Related Topics



Text by Jean Paul Plaza

Photo CC by Vic