A procedure for visualizing the inside of the rectum and colon using a long, flexible, narrow tube with a light and tiny camera on the end of it. Colonoscopy may reveal inflamed tissue, ulcers, polyps, and cancers.
Doctors recommend using colonoscopy to screen for colon and rectal cancer starting at age 50, but people with a family history of polyps or colorectal cancer, a personal history of inflammatory bowel disease (such as ulcerative colitis or Crohn’s disease), or other risk factors for colorectal cancer may benefit from earlier screening. Doctors may also use colonoscopy to reveal the underlying cause of changes in bowel activity, abdominal pain, bleeding from the anus, or unexplained weight loss.
One to three days before the colonoscopy, the patient may be asked to follow a clear liquid diet and take various laxative combinations to help clean out the colon. During the procedure, the patient lies on a table and is given sedatives, anesthesia, or pain medication. The doctor inserts the colonoscope into the anus and through the rectum and slowly guides it into the colon. Air is pumped into the large intestine to help the doctor better view the intestinal lining. He or she may remove any polyps and send them to a lab for testing.
Colon polyps are common in adults and are usually harmless. Some polyps may become cancerous, so removing them early can help prevent colon cancer.