Locations Main Campus: Chesterfield, MO 63017   |   Locations
314-434-1500 314-434-1500   |   Contact Us

Multimedia Encyclopedia

BACK
TO
TOP
 
E-mail Form
Email Results

 
 
Print-Friendly
Bookmarks
bookmarks-menu

Colonoscopy

Colon cancer - colonoscopy; Colorectal cancer - colonoscopy; Colonoscopy - screening; Colon polyps - colonoscopy; Ulcerative colitis - colonoscopy; Crohn disease - colonoscopy; Diverticulitis - colonoscopy; Diarrhea - colonoscopy; Anemia - colonoscopy; Blood in stool - colonoscopy

 

A colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope.

The colonoscope has a small camera attached to a flexible tube that can reach the length of the colon.

How the Test is Performed

 

Colonoscopy is done most often in a procedure room at your doctor's office. It can also be done in the outpatient department of a hospital or medical center.

  • You will be asked to change out of your street clothes and wear a hospital gown for the procedure.
  • You are likely given medicine into a vein (IV) to help you relax . You should not feel any pain. You may be awake during the test and may even be able to speak. You will probably not remember anything.
  • You lie on your left side with your knees drawn up toward your chest.
  • The colonoscope is gently inserted through the anus. It is carefully moved into the beginning of the large intestine. The scope is slowly advanced as far as the lowest part of the small intestine.
  • Air is inserted through the scope to provide a better view. Suction may be used to remove a fluid or stool.
  • The doctor gets a better view as the scope is moved back out. So, a more careful exam is done while the scope is being pulled back.
  • Tissue samples ( biopsy ) or polyps may be removed using tiny tools inserted through the scope. Photos may be taken using the camera at the end of the scope. If needed, procedures, such as laser therapy , are also done.

 

How to Prepare for the Test

 

Your bowel needs to be completely empty and clean for the exam. A problem in your large intestine that needs to be treated may be missed if your intestines are not cleaned out.

Your health care provider will give you the steps for cleansing your bowel. This is called bowel preparation. Steps may include:

  • Using enemas
  • Not eating solid foods for 1 to 3 days before the test
  • Taking laxatives

You need to drink plenty of clear liquids for 1 to 3 days before the test. Examples of clear liquids are:

  • Clear coffee or tea
  • Fat-free bouillon or broth
  • Gelatin
  • Sports drinks without added color
  • Strained fruit juices
  • Water

You will likely be told to stop taking aspirin, ibuprofen, naproxen, or other blood-thinning medicines for several days before the test. Keep taking your other medicines unless your doctor tells you otherwise.

You will need to stop taking iron pills or liquids a few days before the test, unless your provider tells you it is OK to continue. Iron can make your stool dark black. This makes it harder for the doctor to view inside your bowel.

 

How the Test will Feel

 

The medicines will make you sleepy so that you may not feel any discomfort or have any memory of the test.

You may feel pressure as the scope moves inside. You may feel brief cramping and gas pains as air is inserted or the scope advances. Passing gas is necessary and should be expected.

After the exam, you may have mild abdominal cramping and pass a lot of gas. You may also feel bloated and sick to your stomach. These soon go away.

You should be able to go home 1 hour after the test. You must plan to have someone take you home after the test, because you will be woozy and unable to drive. The providers will not let you leave until someone arrives to help you.

When you are home, follow instructions on recovering from the procedure. These may include:

  • Drink plenty of liquids. Eat a healthy meal to restore your energy.
  • You should be able to return to your regular activities the next day.
  • Avoid driving, operating machinery, drinking alcohol, and making important decisions for at least 24 hours after the test.

 

Why the Test is Performed

 

Colonoscopy may be done for the following reasons:

  • Abdominal pain, changes in bowel movements, or weight loss
  • Abnormal changes (polyps) found on sigmoidoscopy or x-ray tests ( CT scan or barium enema )
  • Anemia due to low iron (usually when no other cause has been found)
  • Blood in the stool , or black, tarry stools
  • Follow-up of a past finding, such as polyps or colon cancer
  • Inflammatory bowel disease ( ulcerative colitis and Crohn disease )
  • Screening for colorectal cancer

 

Normal Results

 

Normal findings are healthy intestinal tissues.

 

What Abnormal Results Mean

 

Abnormal test results may mean any of the following:

  • Abnormal pouches on the lining of the intestines, called diverticulosis
  • Areas of bleeding
  • Cancer in the colon or rectum
  • Colitis (a swollen and inflamed intestine) due to Crohn disease, ulcerative colitis, infection, or lack of blood flow
  • Small growths called polyps on the lining of your colon (which can be removed through the colonoscope during the exam)

 

Risks

 

Risks of colonoscopy may include any of the following:

  • Heavy or ongoing bleeding from biopsy or removal of polyps
  • Hole or tear in the wall of the colon that requires surgery to repair
  • Infection needing antibiotic therapy (very rare)
  • Reaction to the medicine you are given to relax, causing breathing problems or low blood pressure

 

 

Open References

References

Chernecky CC, Berger BJ. Colonoscopy - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:358-359.

Itzkowitz SH, Potack J. Colonic polyps and polyposis syndromes. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management . 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 126.

Lieberman DA, Rex DK, Winawer SJ, et al. United States Multi-Society Task Force on Colorectal Cancer. Guidelines for colonoscopy surveillance after screening and polypectomy: a consensus update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology . 2012;143:844-857. PMID: 22763141 www.ncbi.nlm.nih.gov/pubmed/22763141 .

National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: colorectal cancer screening. Version 1.2015. www.nccn.org/professionals/physician_gls/pdf/colorectal_screening.pdf . Accessed February 11, 2016.

 
  • Colonoscopy

    Colonoscopy - illustration

    There are 4 basic tests for colon cancer: a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon, colonoscopy (inspection of the entire colon), and double contrast barium enema. All 4 are effective in catching cancers in the early stages, when treatment is most beneficial.

    Colonoscopy

    illustration

  • Colonoscopy

    Colonoscopy - illustration

    A sample of colon tissue is obtained during a colonoscopy procedure using special instruments. The specimen is sent to the laboratory and fixed with special stains. The specimen is examined under the microscope for abnormal findings, such as cancer or inflammation.

    Colonoscopy

    illustration

    • Colonoscopy

      Colonoscopy - illustration

      There are 4 basic tests for colon cancer: a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon, colonoscopy (inspection of the entire colon), and double contrast barium enema. All 4 are effective in catching cancers in the early stages, when treatment is most beneficial.

      Colonoscopy

      illustration

    • Colonoscopy

      Colonoscopy - illustration

      A sample of colon tissue is obtained during a colonoscopy procedure using special instruments. The specimen is sent to the laboratory and fixed with special stains. The specimen is examined under the microscope for abnormal findings, such as cancer or inflammation.

      Colonoscopy

      illustration

    A Closer Look

     

      Self Care

       

        Tests for Colonoscopy

         
         

        Review Date: 1/28/2016

        Reviewed By: Subodh K. Lal, MD, gastroenterologist at Gastrointestinal Specialists of Georgia, Austell, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

        The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

         
         
         

         

         

        A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.



        Content is best viewed in IE9 or above, Firefox and Google Chrome browser.