Come examination time, seek a practiced hand

Considering a colonoscopy?

Nearly 70% of the colonoscopies in the new study were performed by general surgeons, internists and family practitioners -- not all of whom were likely to have had much experience. Physicians who specialize in colonoscopies tend to be more adept at spotting tumors.

One lesson of the study may be that “patients should seek out board-certified gastroenterologists to do their examinations,” says Dr. Jacques Van Dam, director of endoscopy at Stanford University Medical Center.

Still, no matter how expert the examiner, the accuracy of colonoscopy may well be less than once thought, and patients may want to take that into consideration when deciding whether to have the test.

If they start having new symptoms, for example, they may decide to have another colonoscopy even if they’ve had one recently, says Dr. Nancy Baxter, lead author of the study.

On the other hand, colonoscopy -- though generally safe -- has a 0.2% rate of serious complications (including bowel perforations and bleeding), a rate 10 times higher than any other widely used cancer screening test, Dr. David Ransohoff, a professor of medicine at the University of North Carolina, wrote in an editorial with the study. He noted that with repeated exams, the cumulative rate can be substantial.

Because the chance of harm is always there, patients who are not at high risk for colorectal cancer may even decide on a different type of screening such as testing for blood in the stool, Baxter says. Other tests are less accurate but also less risky.

It’s generally recommended that everyone should have a colonoscopy at age 50 and every 10 years from then on. More frequent colonoscopies are recommended for people at high risk -- including those with a family history of colorectal cancer, those who have had colorectal cancer previously and those with a predisposing condition such as inflammatory bowel disease.

-- Karen Ravn