to get a good colonoscopy…
A recent Canadian study cast doubt on the efficacy of colonoscopy, but there are measures you can take to improve your odds of getting a good test.
Colonoscopy, while certainly not a fun procedure, is recommended as a cancer screening test on all adults beginning at age 50, and for younger people with risk factors (for example a positive family history). Colorectal cancer is the third leading cause of cancer deaths in the U.S. You have a 1 in 19 chance of developing colorectal cancer during your lifetime! Fortunately though, if this cancer is caught early the five-year cure rate is over 90%, so screening and early detection is well worthwhile.
Colonoscopy involves using a flexible endoscope to visualize the entire (5 ft/ 1.5 m) colon, looking for polyps or growths that might be cancerous. Most intestinal cancers begin within colon polyps, and it takes from 5 to 10 years for a polyp (one that is so predisposed) to turn into a cancer. A colonoscopist should biopsy or remove any polyps or growths that looks suspicious. Hopefully suspicious polyps are removed before they have the chance to become cancerous.
While there are other screening methods for colorectal cancer (such as virtual colonoscopy, various x-ray studies, fecal blood and DNA tests), colonoscopy is still considered the “gold standard” —a highly accurate test. So it was surprising when a recent report appeared in the Annals of Internal Medicine casting doubt on the reliability of colonoscopy. This Canadian study showed that many potential cancers were missed, particularly on the right side of the colon, the farthest away and most difficult part of the colon to visualize during a colonoscopy. And an earlier study last year suggested that the more difficult-to-see flat lesions are more likely to turn into cancers than polyps.
One problem with colonoscopy is that, despite a pre-procedure “prep” (a cleanout of the colon of any fecal material using oral laxatives and maybe enemas), many patients still have some residual feces in the colon which can hide some lesions—flat growths in particular. Another issue arising from the Canadian study, is that about a third of the colonoscopies there were not done by gastrointestinal endoscopic specialists; rather, they were done by internists or family practitioners who likely do not have the same skill as a specialist.
You can take some measures to try to get a good colonoscopy for yourself when that time comes:
1. Ensure you are getting the study done by a trained gastrointestinal endoscopic specialist, someone who does a high volume of colonoscopies every year. You might consult this patient guide from the American Society of Gastrointestinal Endoscopy. And for myself, I would only have the study done in a hospital or outpatient facility (rather than a doctor’s office) so I could be properly monitored and sedated.
2. Be compulsive about doing the pre-colonoscopy prep. Even though it is inconvenient to clear out your colon, it is vital so the colonoscopist can get a good look at the walls of your colon, rather than, well….something else! Tell your doctor on your pre-procedure consultation that you want a safe but adequate cleanout so he can do a good job.
3. Also on your pre-colonoscopy consultation, or on the day of the colonoscopy itself, you might consider something I would do myself: mention to your colonoscopist that you have read that some polyps can be missed on the right side of the colon, or if the procedure is hurried….that sort of comment will be remembered by your doctor, and she or he might just make an extra effort to be careful and complete.
