Screening Colonoscopies: Are there Risks?

Screening Colonoscopies: Are there Risks?

Screening Colonoscopies: Are there Risks? 150 150 Dan Frith

No American between 40 and 80 is unaware of the recommendation for screening colonoscopies.  The American Cancer Society recommends that people at “average risk” of colorectal cancer start regular screening at age 45. This can be done either with a test that looks for signs of cancer in a person’s stool, or with an exam that looks at the colon and rectum (a visual exam or colonoscopy).  I have had two screening colonoscopies in my life and am fortunate to report both were normal and no complications were encountered…but not everyone avoids potential complications.

The Yale Center for Outcomes Research and Evaluation (CORE) decided it wanted to quantify the frequency and severity of harm from this common cancer screening, performed in roughly 14 million people each year.  What they found might surprise many: 1.6% of 325,000 otherwise low-risk healthy patients who had a colonoscopy in the year 2010 experienced a complication serious enough to send them to a hospital or emergency department within 7 days.  

A lot of things can go wrong even after colonoscopy in an outpatient setting or an ambulatory surgery center.  Perforations or lacerations to the colon can cause bleeding and hemorrhage or even infections that don’t show up for a day or more; sedative drugs can cause reactions resulting in hypoxia, aspiration pneumonia, and cardiac arrhythmias. 

My Take:  The type and frequency of risks associated with screening colonoscopies does not mean you should avoid following the American Cancer Society’s recommendations.  Colon cancer is easily diagnosed and, if not timely diagnosed, can lead to premature death.  My advice is that if you experience any post colonoscopy abdominal pain or blood in your stool, get to a hospital emergency department promptly.  Tell the doctors about your recent colonoscopy and your concern that your colon may have been perforated or that you are experiencing symptoms from some other complication from the colonoscopy.  An abdominal CT, with contrast, can typically determine if you have a serious problem.  

My last advice relates to the experience of the physician performing your colonoscopy and those who assist in the procedure.  Go to a gastroenterologist – a physician with dedicated training and unique experience in the management of diseases of the gastrointestinal tract and liver.  Gastroenterologists are specialists who receive training in endoscopy (upper endoscopy, sigmoidoscopy, and colonoscopy) by expert instructors. In rural Virginia, I see many general surgeons performing screening colonoscopies.  I prefer to have a doctor who has specialized training in the procedure and who performs colonoscopies with great frequency…not a general surgeon who might take out an appendix today, a gall bladder tomorrow, repair varicose veins two days later, and perform one colonoscopy a month.  Also, if you are having your colonoscopy outside of the hospital setting (like an ambulatory care center), make sure there is an anesthesiologist present at the facility and do not settle for a nurse anesthetist, who is not a medical doctor. If complications from anesthesia occur, you don’t want your life to depend on just how quickly you can be transferred to a nearby hospital with anesthesiologists on staff.

We have previously discussed the risks associated with colonoscopies in multiple posts:

  1. “Routine Procedure” anything but routine




About the author

Dan Frith

Dan Frith has over 25 years of experience representing individuals and families in cases of medical malpractice throughout Virginia. He has been named "Best Medical Malpractice Attorney" by Roanoker Magazine and is a member of the Million Dollar Advocates Forum. To speak with Dan, contact him by email at

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