Colonoscopy
During a colonoscopy, a doctor examines your colon and rectum using a special, flexible instrument (colonoscope), which is inserted into the anus and guided up through to the colon. The colonoscope allows the doctor to view suspicious areas and to take a small tissue sample; he can also use it to perform some surgical procedures, such as cutting out small growths (polyps). Because a colonoscopy requires an empty colon, you will drink laxatives the day before and have an enema on the day. Colonoscopy is performed to investigate changes in bowel habits, blood in stools, and stomach pains and swellings, which could possibly be symptoms of diverticular disease, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), or colon cancer. It is recommended that older adults have routine colonoscopies (even if they do not have any symptoms) to rule out these diseases.
What is it?
Colonoscopy refers to the examination of the colon and rectum (the last parts of the bowel), using a colonoscope, which is a flexible fibre-optic instrument consisting of a lens, a light source, and a tube through which small surgical instruments can be passed.
The procedure can be performed at specially equipped doctor’s rooms but is often done in clinics and hospitals. It takes approximately one hour.
Why is it done?
Colonoscopy is done to investigate symptoms such as:
- Change in bowel habit (diarrhoea or constipation)
- Blood in stool
- Abdominal pain and cramping
- Abdominal swellings or masses
It is used when considering diagnoses such as:
- Diverticular disease
- Inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
- Colon cancer
- Colon polyps
Colonoscopy may be performed as a routine screening procedure i.e. it may be done in the absence of any symptoms.
What happens?
Before – how to prepare
The colon needs to be emptied before the test and this usually involves drinking laxatives in the preceding 24 hours as well as having enemas on the day of the procedure.
You will need to sign a consent form.
During – how the test is done
You will be sedated, but general anaesthetic is not normally needed. You lie on your side, with your knees drawn up towards your chest. The doctor will insert the colonoscope into your anus and gently guide it all the way through your colon. He can look through the colonoscope as well as watching on a TV monitor (via an attached camera). Often, your bowel is inflated with some air, passed through the colonoscope, to make viewing easier. If the doctor sees any abnormal or suspicious areas he may take a biopsy (small tissue sample), using small surgical instruments passed through the colonoscope. In addition, certain surgical procedures can be performed, including the excision of polyps (small growths that may be benign, pre-cancerous, or cancerous).
You may feel some discomfort, cramping, and sensations of pressure, during the procedure, but these are usually fairly mild.
After the test
The sedative will have left you feeling drowsy for a few hours and you will not be able to drive home – you need to arrange for somebody to collect you.
It is important to drink plenty of fluids after the test.
Risks and Compilations
These include:
- Perforation of the bowel
- Bleeding from biopsy sites
- Reactions/side effects to the sedatives used
Colonoscopy is a commonplace procedure these days and is generally considered to be very safe – problems are uncommon.
Special Issues
More and more experts are recommending routine colonoscopy, as a screening test, for older adults. It is wise to discuss this option with your own doctor.
Short Description
During a colonoscopy, a doctor examines your colon and rectum using a special, flexible instrument (colonoscope), which is inserted into the anus and guided up through to the colon.
Keywords
colonoscopy, colonoscope, colon