Final answer:
Patients with adenomatous polyps detected by sigmoidoscopy should undergo a colonoscopy for thorough examination and possible removal of polyps, playing a vital role in colorectal cancer prevention.
Step-by-step explanation:
All patients with adenomatous polyps found on screening sigmoidoscopy should have a follow-up procedure to inspect the entirety of the colon. A sigmoidoscopy allows doctors to use a camera to inspect the rectum and lower third of the colon, which is a common site for colorectal cancer. However, it does not allow examination of the entire colon.
For full examination, a colonoscopy is required because this procedure not only identifies precancerous polyps, but it also allows for their removal, thus preventing potential progression to cancer. The colonoscopy serves both a diagnostic and therapeutic role in cancer prevention. Additionally, patients over the age of 50 are recommended to undergo screening for fecal occult blood tests and colonoscopy.