Flexible sigmoidoscopy is effective in reducing the rates of new cases and deaths due to colorectal cancer, reveals research. In a study that spanned almost 20 years, researchers found that overall colorectal cancer mortality (deaths) was reduced by 26 percent and incidence (new cases) was reduced by 21 percent as a result of screening with sigmoidoscopy. These results appeared online, ahead of print, on May 21, 2012, in the New England Journal of Medicine, Digestive Disease Week, a scientific conference.
Sigmoidoscopy involves examination of the lower colon using a thin, flexible tube-like instrument, called a sigmoidoscope, to view the anus, rectum, and sigmoid colon (see Figure 1). Sigmoidoscopy has fewer side effects, requires less bowel preparation, and poses a lower risk of bowel perforation (an uncommon event, when the screening instrument pokes a hole in the intestine) than colonoscopy, in which a similarly flexible, but longer, tube is used to view the entire colon.