The Basics
Colonoscopy is a test that enables your doctor to look at the inner lining of your large bowel (rectum and colon) to screen for abnormalities such as ulcers, polyps, inflammation, bleeding, and cancers.
A thin, flexible, tube-like instrument called the colonoscope is used to conduct this test. The small camera on the colonoscope allows the doctor to look at the inside of your bowels on a screen.
A colonoscopy is performed for a variety of reasons, such as:
- investigating symptoms such as blood in stool, chronic constipation or diarrhea, a change of bowel habits, unexplained abdominal pain, or anemia
- investigating abnormal results from barium enema test
- screening for colon cancer
- collecting tissue samples for a biopsy
Even if you do not have any symptoms, a colonoscopy should be conducted at least every 10 years from the age of 50 onwards. It should be done more frequently for people with a family history of colon cancer or polyps.
Risks and precautions
Colonoscopy is usually a straightforward and safe procedure. However, there are some risks of complications or side effects, including:
- fever
- dizziness
- excessive bleeding at the site of a biopsy or polyp removal
- reacting to the sedative during the exam
- severe abdominal pain
- a tear in the colon wall, which may need to be repaired with surgery
- vomiting
Get immediate medical assistance if you experience any of these complications or side effects.
It is important that you understand all the risks of complications and side effects of the test, and what you or your doctor can do to avoid them. Make sure that your doctor is aware of all your concerns.
Before the test
It is important that you fully understand what the test involves beforehand. Ask your doctor to explain the risks, benefits, and drawbacks of the test, and don't be shy to probe further until you are comfortable with your doctor's responses.
You will be asked to take a colon preparation 1 to 2 days before the test to clean out the colon so that your doctor can see it better. The colon preparation will cause you to have frequent loose stools or diarrhea. In addition, you will be asked to stay on a clear liquid diet (e.g., water, coffee, tea, water, clear broth, ginger ale, clear juices) 1 to 2 days before the test.
It is important to drink plenty of clear fluids to stay hydrated. You may be asked to stop drinking liquids 6 to 8 hours before the test. You may also be asked to use an enema 30 to 60 minutes before the colonoscopy to further clean out your colon.
You may be given pain medication or a sedative to help you relax before the test. Plan to have someone drive you home afterwards.
If you are taking any prescription or over-the-counter (non-prescription) medications, supplements, or herbal products, make sure you inform your doctor or pharmacist. Ask them whether it is necessary for you to stop taking any of these medications and products before the test. It is also important to tell them if you have allergies to certain medications or have certain medical conditions.
Also, tell your doctor if you are pregnant or suspect that you might be pregnant.