Many physicians are unfamiliar with the evidence that screening reduces mortality. Furthermore, physicians may not know the current protocols for screening. Many assume that guaiac testing in the office, performed on the glove used in a rectal examination, constitutes fecal occult blood testing. Finally, physicians may not know which types of polyps are premalignant or, having detected polyps on endoscopy or barium enema, which sizes require biopsy. The next barrier is attitudinal.
Physicians can know the facts about colorectal cancer screening but remain uneager to act.
For many years, colorectal cancer screening was the focus of conflicting guidelines and controversy. Not until 1996 did the U.S. Preventive Services Task Force abandon the position that evidence was insufficient to make a recommendation. Some physicians who know the data are not impressed by the magnitude of benefit. There can also be barriers to the ability to perform effective colorectal cancer screening. Even enthusiastic physicians cannot screen patients if they lack time, patient cooperation, office help, ease of referral to gastroenterologists or insurance coverage.