A review of hospital discharge data in California revealed that interruptions in Medicaid coverage increased the risk of hospitalization for ambulator

By GINA KOLATA -Published December 16, 2008 - New York Times For years, many doctors and patients thought colonoscopies, the popular screening test for colorectal cancer, were all but infallible. Have a colonoscopy, get any precancerous polyps removed, and you should almost never get colon cancer. Then, last spring, researchers reported the test may miss a type of polyp, a flat lesion or an indented one that nestles against the colon wall. And now, a Canadian study, published Tuesday in the journal Annals of Internal Medicine, found the test, while still widely recommended, was much less accurate than anyone expected. In the new study, the test missed just about every cancer in the right side of the colon, where cancers are harder to detect but about 40 percent arise. And it also missed roughly a third of cancers in the left side of the colon.