A study out of the University of Toronto found that colonoscopies performed by family physicians missed diagnosing colon cancer in their patients 77 percent more often that gastroenterologists. Again, if you’re going to have the procedure in the first place you probably want to make sure it’s going to be as accurate as possible and a specialist will be a very good place to start.
This finding on colonoscopies also reminds me of two pieces I wrote on not long ago. One was that doctors who were under-experienced in specific procedures were more likely to error in their work while performing those procedures. This would imply that have having a gastroenterologist perform your colonoscopy would really only maximize the tests accuracy if that physician was well experienced in the procedure. The published findings had this to say on the subject.
"Evidence suggests that physicians who perform fewer than 100 procedures per year or who have performed fewer than 50 procedures in their lifetime are more likely to perform incomplete colonoscopies than those who performed higher volumes. Low volumes are an issue in Ontario; according to our study, over 25 percent of physicians who performed colonoscopies in 2001/2002 performed fewer than 100 procedures."25 percent seems high; maybe the stats are different in your area however. But if this number is accurate then the chances are high your doctor might be slightly under-experienced in the procedure. You might just want to inquire how experienced he or she is before committing to the colonoscopy… of course this is a matter of personal preference; so come to your own conclusions.
Also, I’m reminded of the argument for CTC Scanning of your colon as an alternative to colonoscopy. The CTC scan is less accurate (~10 percent miss rate) than a colonoscopy but if you’re uncomfortable with the colonoscopy procedure and can’t get around having an inexperienced family physician administer it, maybe you might want to consider decreasing your risks for colon cancer and having the CTC scan instead.
Canadian Journal of Gastroenterology, July 2007