What is the difference between a sigmoidoscopy and a colonoscopy? Who should have these tests?
Sigmoidoscopy and colonoscopy are ways to look at the inside of the colon and rectum. In both tests, the doctor uses a thin, flexible tube with a light to check for polyps (small sacs on the lining of the colon that may become cancer), tumors, or abnormal areas in the rectum and colon.A sigmoidoscopy examines the lower colon only. A colonoscopy involves the entire colon.Doctors use these tests to check for cancer of the colon and rectum. How well these tests can find cancer has not been studied thoroughly. Sigmoidoscopy is part of a current large clinical trial (research study with people), called the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO), sponsored by the National Cancer Institute. The study will look at whether sigmoidoscopy and other tests decrease cancer deaths. Other ways to check for cancer of the colon and rectum include the fecal occult blood test (stool sample) and a barium enema (a white, chalky solution that outlines the colon and rectum during
