Colonoscopy is a test that allows your doctor to look at the inner lining of your large intestine camera.gif (rectum and colon). He or she uses a thin, flexible tube called a colonoscope to look at the colon. A colonoscopy helps find ulcers, colon polyps, tumors, and areas of inflammation or bleeding. During a colonoscopy, tissue samples can be collected (biopsy) and abnormal growths can be taken out. Colonoscopy can also be used as a screening test to check for cancer or precancerous growths in the colon or rectum (polyps).
The colonoscope is a thin, flexible tube that ranges from 48 in. (125 cm) to 72 in. (183 cm) long. A small video camera is attached to the colonoscope so that your doctor can take pictures or video of the large intestine (colon). The colonoscope can be used to look at the whole colon and the lower part of the small intestine. A test called sigmoidoscopy shows only the rectum and the lower part of the colon.
Before this test, you will need to clean out your colon (colon prep). Colon prep takes 1 to 2 days, depending on which type of prep your doctor recommends. Some preps may be taken the evening before the test. For many people, the prep is worse than the test. The bowel prep may be uncomfortable, and you may feel hungry on the clear liquid diet. Plan to stay home during your prep time since you will need to use the bathroom often. The colon prep causes loose, frequent stools and diarrhea so that your colon will be empty for the test. If you need to drink a special solution as part of your prep, be sure to have clear fruit juices or soft drinks to drink after the prep because the solution may have a salty or unpleasant taste.
Colonoscopy is one of many tests that may be used to screen for colon cancer. Other tests include sigmoidoscopy, stool tests, and computed tomographic colonography. Which screening test you choose depends on your risk, your preference, and your doctor. Talk to your doctor about what puts you at risk and what test is best for you.
Colonoscopy is done to:
- Check for colorectal cancer or polyps.
- This test is recommended by many experts and groups, including the American Cancer Society (ACS) and the U.S. Preventive Services Task Force (USPSTF).
- These groups recommend routine testing for people age 50 and older who have a normal risk for colorectal cancer.
- Your doctor may recommend earlier or more frequent testing if you have a higher risk of colorectal cancer. Talk to your doctor about when you should be tested.
- 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 CT scan, MRI, virtual colonoscopy, stool test, or barium enema.
- Watch or treat inflammatory bowel disease (IBD).
- Check for the cause of long-term, unexplained belly pain.
Before you have a colonoscopy, tell your doctor if you:
- Are taking any medicines, such as insulin or medicines for arthritis. Check with Dr Stuart about which medicines you need to take on the day of your test.
- Are allergic to any medicines, including anesthetics.
- Have bleeding problems or take aspirin or other blood thinners.
- Had an X-ray test using barium, such as a barium enema, in the last 4 days.
- Are or might be pregnant.
You may be asked to stop taking aspirin products or iron supplements 7 to 14 days before the test. If you take blood-thinning medicines regularly, discuss with your doctor how to manage your medicine.
You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.
Colonoscopy may be done in a doctor's office, clinic, or a hospital. The test is most often done by a doctor who works with problems of the digestive system (gastroenterologist). The doctor may also have an assistant. Some family doctors, internists, and surgeons are also trained to do colonoscopy.
During the test, you may get a pain medicine and a sedative put in a vein in your arm (IV). These medicines help you relax and feel sleepy during the test. You may not remember much about the test.
You may feel the need to have a bowel movement while the scope is in your colon. You may also feel some cramping. Breathe deeply and slowly through your mouth to relax your belly muscles. This should help the cramping. You will likely feel and hear some air escape around the scope. There is no need to be embarrassed about it. The passing of air is expected. You may be asked to change your position during the test.
Your doctor will look at the whole length of your colon as the scope is gently moved in and then out of your colon.
The doctor may also use tiny tools, such as forceps, loops, or swabs, through the scope to collect tissue samples (biopsy) or take out growths. Usually, people do not feel anything if a biopsy is done or if polyps are taken out.
The scope is slowly pulled out of your anus and the air escapes. Your anal area will be cleaned with tissues. If you are having cramps, passing gas may help relieve them.
The test usually takes 30 to 45 minutes, but it may take longer, depending upon what is found and what is done during the test.
After the test, you may need to stay at the clinic for 1 to 2 hours. Or you may be allowed to leave sooner with the person who will be driving you home. Your doctor will tell you when you can eat your normal diet and do your normal activities. Drink a lot of fluid after the test to replace the fluids you may have lost during the colon prep, but do not drink alcohol.
If you received a sedative during the test, do not drive, operate machinery, or sign legal documents for 24 hours after the test. Arrange to have someone drive you home after the test.
After the test, call your doctor immediately if you:
- Have heavy rectal bleeding.
- Have severe belly pain.
- Develop a fever.
- Are very dizzy.
- Are vomiting.
- Have a swollen and firm belly.
The colon prep will cause diarrhea. Some people also have cramping.
During the test, you may feel very sleepy and relaxed from the sedative and pain medicines. You may have cramping or feel brief, sharp pain when the scope is moved or air is blown into your colon. As the scope is moved up the colon, you may feel the need to have a bowel movement and pass gas. If you are having pain, tell your doctor.
The suction machine used to remove stool (feces) and secretions may be noisy but does not cause pain.
You will feel sleepy after the test for a few hours. Many people say they do not remember very much about the test because of the sedative.
After the test, you may have bloating or crampy gas pains and may need to pass some gas. If a biopsy was done or a polyp taken out, you may have traces of blood in your stool (feces) for a few days. If polyps were taken out, your doctor may instruct you to not take aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) for 7 to 14 days.
There is a small chance for problems from a colonoscopy. The scope or a small tool may tear the lining of the colon or cause bleeding.
Colonoscopy is a test that allows your doctor to look at the inner lining of your large intestine (rectum and colon). If a sample of tissue (biopsy) was collected during the colonoscopy, it will be sent to a lab for tests.
- Samples of colon tissue are usually sent to a pathology lab, where they are looked at under a microscope for diseases.
- Other samples of colon tissue may be sent to a microbiology lab to see whether an infection is present.
Your doctor may be able to tell you the results immediately after the procedure. Other test results are ready in 7 to 10 days. Test results for certain infections may be ready in several weeks. Our nurse will contact you by phone 2 weeks after the procedure to notify you of the results. Your results are also sent to your local doctor, and an appointment will have been made to see Dr Kostalas for follow-up.
Reasons you may not be able to have the test or why the results may not be helpful include:
- Having a barium enema within a week before the test. Barium can block your doctor's view of the colon.
- Not doing a good bowel prep before the test. If you still have stool (faeces) in the colon, your doctor may cancel the test and you will have to reschedule and do the colon prep again.
- Having a colon that has many turns, past surgery on the colon, or a lot of pain during the test.
- Taking iron supplements. This may make your stool turn black and make it hard to clean out the colon. Do not take iron supplements for several days before a colonoscopy.
- Drinking red or purple fluids, such as grape juice or fruit punch.
- Eating red or purple foods, such as grape ice pops or cherry gelatin.