Dr Marios Efthymiou MBBS MD FRACP


What is colonoscopy and why is it performed?

Colonoscopy allows your doctor to examine the lining of the large bowel (colon) and it is the most accurate test for diagnosing early cancer of the colon and colon polyps (pre-cancer). Colonoscopy also helps evaluate symptoms such as rectal bleeding, abdominal pain, constipation, diarhhoea and abdominal pain.

Your doctor will use a thin, flexible tube called a colonoscope that has a built-in camera. This allows your doctor to view images of the colon on a monitor. Your doctor can also pass instruments through the colonoscope to treat conditions such as polyps, internal bleeding and haemorrhoids.

What preparations are required?

The colon has to be cleared of stool for a thorough and safe examination. Some medications may need to be discontinued before colonoscopy. Specific details about how to prepare for colonoscopy can be found here.

What happens during colonoscopy?

Your doctor will first discuss the risks of the procedure with you and address any questions you may have. You will then meet your anaesthetist who will discuss all aspects of the anaesthetic. Following this you will be taken to the procedure room. You'll then lie on your side, and a needle will be placed in your hand or arm. This is used to administer the anaesthetic. Once you are completely asleep your doctor will pass the endoscope through your anus and into the rectum and also advance the colonoscope into the caecum or start of the large bowel. The procedure usually takes around 30-45 minutes.

What are polyps and why are they removed?

Polyps are abnormal growths in the colon. Most polyps are not cancerous, however all cancers begin as a polyp. For this reason when polyps are encountered during colonoscopy they are removed to reduce the risk of developing colon cancer in the future. A number of techniques may be used to remove polyps dependent on the size and other characteristics of a polyp.

What happens after a colonoscopy?

You will be monitored until the anaesthetic has worn off. Your doctor will explain the results of the examination to you and will provide you with a written report of your procedure for your GP. You will be able to eat after you leave unless your doctor instructs you otherwise. Because of the anaesthetic, your judgement and reaction time will be impaired for the rest of the day. You will need someone to drive you home and stay with you.

What are the possible complications of colonoscopy?

Complications after colonoscopy are rare. The risk of serious complications with standard colonoscopy is less than one case per one thousand procedures. The most serious complication is perforation (a hole or tear in the gastrointestinal tract wall) and this routinely needs surgery. Other risks include bleeding from a biopsy site or polyp removal site. This is uncommon however it may lead to transfusion or admission to hospital. Some patients may have a reaction to the anaesthetic or complications from heart or lung disease.
Although complications after colonoscopy are uncommon, it's important to recognise complications and treat them early.

Contact your doctor immediately if you have a fever after the test or if you have abdominal pain, or bleeding, including black stools. Bleeding can up to two weeks after the procedure.If you have any concerns following your test, you should contact your doctor right away.