What is a Colonoscopy?
A colonoscopy is a camera-based examination in which a thin, flexible tube, usually thinner than a finger, is passed through the back passage to examine the inside of the rectum and large intestine (colon).
During the examination, you will usually lie on your side while the doctor views the inside of your colon on a monitor. If appropriate, you may also be able to see the images on the screen. A straightforward diagnostic colonoscopy may take around 15–20 minutes; it can take longer if a biopsy, polyp removal or another intervention is required.
With Good Preparation, a Manageable Examination
During colonoscopy, you may feel some pressure, cramping or bloating. Many patients find the bowel preparation on the day before to be the most inconvenient part, but proper preparation is essential for a clear and effective examination.
Direct Visual Examination
A flexible camera allows the doctor to examine the lining of the colon directly.
Temporary Pressure or Bloating
You may experience pressure, cramping or bloating; the clinical team will help keep you as comfortable as possible.
Preparation Matters
The bowel preparation on the day before cleans the colon so the doctor can see its lining clearly.
Diagnosis & Treatment
When appropriate, a biopsy can be taken or certain polyps can be removed during the same procedure.
What Happens Before & During Colonoscopy?
For a successful colonoscopy, the colon needs to be thoroughly clean. Follow the bowel preparation instructions provided by your doctor or the endoscopy centre.
Bowel Preparation
On the day before the examination, follow the prescribed diet and bowel-cleansing medicine instructions to empty and clean the colon.
Positioning
You will usually be asked to lie comfortably on your side during the examination.
Camera Examination
The flexible colonoscope is passed through the back passage while the doctor carefully examines the inside of the large intestine.
Biopsy or Polyp Removal if Needed
If clinically indicated, tiny tissue samples may be taken or suitable polyps may be removed during the procedure.
Sedation is an Optional Comfort Choice
If you are anxious, concerned about discomfort or would prefer a more relaxed experience, sedation may be considered after clinical assessment. Sedation is a comfort option and is not necessarily the same as general anaesthesia. Depending on the medication and level of sedation used, you may feel sleepy and relaxed, and you may remember little or none of the procedure.
Reasons Your Doctor May Recommend a Colonoscopy
Depending on your age, family history, symptoms and previous test results, colonoscopy may be recommended for screening, diagnosis or treatment.
More Than a Visual Test — Biopsy or Polyp Removal When Needed
During colonoscopy, the doctor may take a small tissue biopsy when clinically indicated. Certain polyps can also be removed during the same procedure. Laboratory examination can then help determine the type of polyp and assess inflammation or possible cancerous changes.
An Important Role in Colorectal Cancer Prevention
One of the major advantages of colonoscopy is that it can do more than detect abnormalities. Certain precancerous polyps can be identified and removed during the same procedure, helping reduce the risk of colorectal cancer. The preparation can be inconvenient, but it is temporary, and the examination itself is usually completed within a relatively short time.