Risks Associated with Colonoscopy Should be Considered

The risks associated with colonoscopy should be considered when evaluating its incremental benefit over less invasive screening tests, according to researchers from Kaiser Permanente and the Centers for Disease Control and Prevention (CDC). The study, “Complications of Colonoscopy in an Integrated Health Care Delivery System,” appears in the current issue of Annals of Internal Medicine.

Researchers identified patients receiving colonoscopy and followed them for 30 days for evidence of hospitalization for procedure-related complications.

During colonoscopy, precancerous polyps can be removed and biopsies can be done on tissue samples. The rate of complications following colonoscopy, even colonoscopy without biopsy, is higher than for other colorectal cancer screening tests, including flexible sigmoidoscopy, according to Theodore Levin, MD, a Kaiser Permanente clinician and researcher and the lead author of the study.

“Delayed bleeding was not uncommon, suggesting that patients should be advised about their risk and that screening centers should have follow-up procedures in place to monitor delayed complications,” he said.

Over 60 percent of the post-polyp removal bleeding episodes occurred in patients with polyps smaller than one centimeter, the ones least likely to become cancer or develop into a serious problem, said Levin. “Being able to better define which polyps are high risk before removing them, would make colonoscopy a substantially safer procedure,” he said, explaining that techniques to accomplish this continue to improve.