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Colonoscopy

Colonoscopy Introduction

A colonoscopy is a test to look at the inside of your colon. The colon is the large intestine and the last part of your digestive system. Its job is to dry, process, and eliminate the waste left after the small intestine has absorbed the nutrients in food. The colon is about 3-5 feet long. It travels from the lower right corner of your abdomen (where the small intestine ends) up to your liver, across your body to the spleen in the upper left corner and then down to form your rectum and anus.

The doctor will use an instrument called the colonoscope to perform a colonoscopy. It is a long (about 3 ft), thin (about 1 in), flexible fiberoptic camera that allows the doctor to visualize your entire colon.

Your doctor may order a colonoscopy to investigate many different diseases of the colon.
- Colonoscopy is best known for its use as a screening tool for the early detection of colorectal cancer.
  - Colorectal cancer is the second leading cause of cancer deaths in the United States.
  - Colon cancer develops from growths within the wall of the intestine such as polyps or tumors.
  - These growths often take 5-10 years to develop and may not cause many symptoms.
  - You may not have any symptoms of colon cancer, but having a close relative with the disease increases your risk for the disease compared to the general public.
  - Most people who develop polyps do so after age 50, so the American College of Gastroenterology (the digestive specialists) recommends screening examinations every 5 years for early detection and removal of these cancer-causing growths after that age.
- Colonoscopy is also used to investigate other diseases of the colon.
  - Colonoscopy may be used to find the place and cause of bleeding as well as to check areas for irritation or sores in your colon.
  - These colon problems can cause unexplained changes in bowel habits.
  - Pain, bloody diarrhea, and weight loss can be caused by inflammation of the bowel, which may be the result of Crohn disease or ulcerative colitis.
  - These inflammatory digestive diseases tend to occur in young adults and, if undetected, can produce chronic symptoms and increase the risk of colon cancer.
Colonoscopy is used when there is concern that a disease of the colon may exist.
- Your doctor may recommend this test if other screening tests such as a manual rectal examination, a hemoccult test to find hidden blood in your feces, or a barium enema (a test in which barium is used to make your colon visible on an x-ray) suggest that further information is needed to make a diagnosis.
- A colonoscopy may be required when symptoms of digestive disease or other warning signs are present.
  - Rectal bleeding (which may appears as bright red, very dark, or black)
  - Pain in the lower abdomen
  - Changes in bowel habits
  - Nondietary weight loss
- Only doctors who specialize in the study of digestive disease, have special training in endoscopy, and are certified to perform colonoscopy qualify to perform this procedure.
  - As with any skill, performance improves with experience.
  - The American Society for Gastrointestinal Endoscopy suggests that a doctor perform at least 200 procedures to become technically competent at diagnostic colonoscopy.