Colon cancer is the third most common cancer in men and women. Colonoscopy is used to look for problems in your colon and detect early signs of cancer when it’s most treatable.

What’s the purpose of a colonoscopy?

Colonoscopy is used to screen for colorectal cancer. Screening means looking for cancer in people who don’t have any symptoms of the disease. A colonoscopy may be used to check and treat things such as:

  • Colon polyps
  • Tumors
  • Ulceration
  • Redness or swelling (inflammation)
  • Pouches (diverticula) along the colon wall
  • Narrowed areas (strictures) of the colon
  • Any objects that might be in the colon

Colonoscopy may also be used to find the cause of unexplained, long-term (chronic) diarrhea or bleeding in the GI (gastrointestinal) tract. It can also be used to check the colon after cancer treatment. Colonoscopy may be used when other tests (such as a barium enema, CT colography, or sigmoidoscopy) show the need for more testing.

Your doctor may have other reasons to recommend a colonoscopy. Most colonoscopies are done on an outpatient basis; some are done during a hospital stay.

What is a colonoscopy?

Colonoscopy is a procedure that checks the inside of your entire large intestine or colon.

The procedure is done using a long, flexible tube (a colonoscope) that is placed through the rectum and into the colon. The tube has a light and tiny camera on one end, allowing the doctor to examine the colon and detect possible problems.

During a colonoscopy, the doctor may remove tissue or abnormal growths (polyps) for further examination. He or she may also be able to treat problems that are found. Colonoscopies are typically performed under mild sedationso you remain comfortable during the procedure.

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