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What is a colonoscopy?

Colorectal cancer

Colonoscopy is a direct visualization of one’s complete colon and rectum all the way to the lower end of the small intestine via the use of a flexible, lighted camera called a colonoscope. The procedure allows the clinician to find polyps and remove them right then, preventing them from becoming cancerous.

If other abnormalities are suspected, the physician can obtain a sample of the tissue and test it for malignancy. If a region of diseased colon is found, it can be evaluated and treated before it becomes more problematic.

On average, 15 percent of women and 25 percent of men age 50 or older will have precancerous polyps detected on colonoscopy. Not everyone who has polyps will go on to develop colon cancer; however, removing potentially precancerous polyps will greatly reduce the risk.

What can I expect during a colonoscopy?

The day before your procedure you will drink a laxative preparation to clean the colon out.

Prior to the procedure, you will be given medications to relax you and block pain. You should feel very comfortable. Some patients may report feeling a sensation of pressure, but rarely pain. The sedative also affects memory, and many people have no memory of ever having the colonoscopy. In some cases, colonoscopy can be done without sedation. However, sedation helps make patients comfortable during the procedure.

When you awaken or the medication wears off, you will need a responsible driver to take you home. Your doctor will notify you of the results. If there are no polyps or other issues, you may not need another colonoscopy for 10 years.

What causes polyps?

Researchers are unsure what causes polyps. Having certain risk factors and engaging in some unhealthy behaviors are thought to make colonic polyps more likely. You may have a higher risk if you have:

  • A family history of polyps or colon cancer
  • Previously had polyps
  • Had ovarian or uterine cancer before the age of 5
  • Unhealthy behaviors that may contribute to the growth of colonic polyps include:
    • Smoking
    • Being overweight
    • Drinking alcohol
    • Lack of exercise
    • Eating a diet rich in fats

Why is screening so important?

Most colon cancers originate from small, non-cancerous (benign) tumors, called polyps. These polyps form on the inner walls of the large intestine. Some of them may grow into malignant colon cancers over time if they are not removed. Since the polyps typically cause no pain or problems, the best defense is to find them before they become cancerous and remove them, thus eliminating the chance they may become cancerous.

Screening can also discover colon cancer early, when treatment can lead to a cure.

Who should have a colonoscopy?

A colonoscopy is recommended for:

  • Everyone age 50 and older
  • Individuals with a family history of colorectal cancer or polyps
  • Those with a personal history of inflammatory bowel disease
About Maggie Ward

Maggie Ward is an oncology nurse navigator with the Via Christi Cancer Institute.