Do You Really Need That Colonoscopy?

Only one in five US family physicians follow practice guidelines for colorectal cancer screening, according to an article published by National Cancer Institute scientists in the Journal of General Internal Medicine.  This results in either overuse or underuse of screening tests.    

The authors of the study surveyed 1,266 physicians taking part in a 3-year survey done by the National Cancer institute.  The screening tests listed were fecal occult blood testing (FOBT), flexible sigmoidoscopy, colonoscopy, and double-contrast barium enema.  Roughly 20% of the doctors followed the practice guidelines for all the tests they recommended, while 40% followed guidelines for some of the tests, and 40% didn’t followed the guidelines for any of the tests.   

Guidelines in place at the time of the survey recommended routinely screening starting at 50 years of age, with FOBT every year, flexible sigmoidoscopies or double-contrast barium enema every 5 years, and colonoscopy every 10 years.  The more guideline-adherent physicians tended to be younger, board certified, users of electronic health records, and in group practices. 

Colonoscopy was the one screening procedure that physicians recommended more frequently than the guidelines called for.  Such overuse may result in unnecessary follow-up visits for patients and exposure to the risk of screening complications.  (At my first colonoscopy in 1982 I was told there was a 1% chance of intestinal perforation and a 1% chance of hemorrhage requiring a transfusion.)  It’s also relevant that colonoscopy is the most expensive colorectal screening method.

Roughly 17% of physicians recommended longer intervals between contrast enemas than the guidelines, and 11% suggested longer intervals between FOBT exams.  This underuse of screening could mean that fewer early stage or pre-invasive cancers are detected in time. 

Importantly, fewer than 5% of physicians waited until the patients were past 50 to recommend starting screening, and many of them ‘jumped the gun’ and encouraged routine testing before 50. 

So patients, you should know the guidelines, and not bug your doctor too early in your life, or too often for re-testing - UNLESS you have symptoms of bowel disease (pain, change in bowel habit, weight loss, etc.), in which case screening guidelines don’t apply.  Get diagnosed quickly!