It was strongly believed since its launch that the doctor examining the patients through Colonoscopy would find and cut out any polyps, which is the main source of most colon cancers. But, now a study findings published in The New England Journal of Medicine says that the doctors performing the procedure too rapidly may miss out some polyps resulting in the development of life-threatening cancers. Performances of 12 highly experienced and board certified gastroenterologist in private practice, who had done at least 3000 colonoscopies each, were monitored under this Illinois study providing a graphical illustration. The illustration showed different results given by different doctors performing the procedures, proving how wrong the assumptions could be. It was found that the doctors spending six minutes or more searching for polyps (minimum time recommended in the professional literature) detected better growths than the ones who did the procedure more quickly. It also found that those who spent more time were 10 times better in finding adenomas than others who spent only fewer times on examining the colon. A Colonoscopy entails inserting a small scope through the rectum to the top of the patient's colon; the scope is slowly withdrawn while the doctor looks for polyps on the colon's interior walls. Such growths are typically snipped out to preclude the possibility they might become cancerous. Gastroenterologists say that though colonoscopies helps in preventing colon cancer, there is a pressing need for better quality control. The experts suggested: "the onus remains on patients to ask for data on how their polyp detection rates are compared to the national norms and about how proficient their doctors are." The issue is of great concern to doctors and patients alike, said Dr. Robert E. Schoen, a gastroenterologist at the University of Pittsburgh Cancer Institute. To conclude, the Rockford groups, who have decided to spend at least eight minutes on the procedure looking for polyps were able to increase its polyp detection rate by 50 %.