Polyps are growths in the lining of the bowel wall. They vary in their shape, size and location within the bowel. They may be single or multiple.
There are different varieties of polyps but those which are associated with bowel cancer are termed adenomatous polyps or simply adenomas. This variety of polyp is important because there is strong evidence that some adenomas may undergo malignant change to produce bowel cancer. Patients who are found to have adenomas are considered at risk of developing bowel cancer. This risk is difficult to quantify. It varies from patient to patient and usually requires periodic surveillance by telescopic examination of all of the large bowel (colonoscopy).
Polyps rarely cause symptoms. Sometimes they may cause bleeding.
Colonoscopy is the most accurate test to diagnose polyps. The purpose is to obtain a clear view of the whole length of the inner surface of the bowel, to search for and remove any polyps found, and have them examined under the microscope. Up to 90% of polyps can be safely and completely removed by colonoscopy.
If adenomas are confirmed by a pathologist, it is recommended that the patient have regular checks by repeated colonoscopy. The frequency of examinations varies and this needs to be discussed with the doctor who performed the colonoscopy.