What is a colonoscopy?
Colonoscopy is a medical procedure where a long, flexible, tubular instrument called the colonoscope is used to view the
entire inner lining of the colon (large intestine) and the rectum.
The purpose of the colonoscopy is to inspect the lining of the large intestine (colon), looking for abnormalities. Abnormal areas may be destroyed, biopsied or removed through a fiber-optic flexible viewing instrument called a colonoscope. Small polyps are usually destroyed in place with a cautery. Larger polyps are removed using a cautery and a special wire snare. Obvious cancers are simply biopsied and surgical removal is scheduled for a later date. Tissue removed with the biopsy forceps or snare, which can be retrieved, will be examined microscopically by a pathologist.
A colonoscopy is generally recommended when the patient complains of rectal bleeding or has a change in bowel habits and other unexplained abdominal symptoms. The test is frequently used to test for colorectal cancer, especially when polyps or tumor-like growths have been detected using the barium enema and other diagnostic tests. Polyps can be removed through the colonoscope and samples of tissue (biopsies) can be taken to test for the presence of cancerous cells.
The test also enables the physician to check for bowel diseases such as ulcerative colitis and Crohn's disease. It is a necessary tool in monitoring patients who have a past history of polyps or colon cancer.