What is a Colonoscopy and When Do I Need One?

Colonoscopy is best known for its use as a screening test to check for cancer or precancerous growths in the colon or rectum. It is also used to detect other changes or abnormalities.

A thin, flexible tube is used to look at the colon. A camera at the end can help the doctor find ulcers, colon polyps, tumors and areas of inflammation or bleeding. Tissue samples can be collected and abnormal growths can be removed.

Colorectal cancer is the third leading cause of cancer deaths in the United States. It develops from growths within the wall of the intestine such as polyps or tumors. These growths can take five to ten years to develop and many not cause many symptoms.

Colonoscopy is also used to investigate other diseases of the colon:

  • Check for the cause of blood in the stool or rectal bleeding.
  • Check for the cause of dark or black stools.
  • Check for the cause of chronic diarrhea.
  • Check for the cause of iron deficiency anemia.
  • Check for the cause of sudden, unexplained weight loss.
  • Check the colon after abnormal results from a stool test or a barium enema test.
  • Watch or treat inflammatory bowel disease
  • Check for the cause of long-term, unexplained belly pain.

    Many people develop polyps after age 50, so the American College of Gastroenterology recommends screening examinations every 10 years for early detection and removal of these cancer-causing growths after that age. People with a higher risk, such as personal or family history, African Americans, or those with a history of inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease, may need to be every 5 years or sooner. Talk to your doctor about when you should be tested. 

    By Joseph Lamb, MD, ThedaCare Physicians-New London.