What is a colonoscopy?

A colonoscopy is a type of endoscopy that is used to examine the colon and small intestine in order to detect any abnormalities (inflammation, ulcers, etc.). The procedure usually lasts around 15-20 minutes. 

What does a colonoscopy involve?

It is performed using a thin tube (endoscope) that is inserted through the anus and has a video camera at the end to record the organs and walls it passes through.

Why is it performed?

A colonoscopy may be performed for various reasons:

Preparing for colonoscopy

Before the test you should follow instructions for cleansing the bowel to make it easier for the doctor to observe it. This will involve drinking only liquids in the 24 hours before the procedure, and taking a solution that will help you empty your bowels.

During the procedure, you will be partially or fully sedated. You will be placed on your side and the doctor will insert the endoscope through the anus to pass through your large intestine.

What do you feel during the procedure?

A colonoscopy is usually well tolerated and is rarely painful. At most, you will feel pressure, swelling, or cramping during the procedure. Less than one per cent of patients will experience serious complications.

Meaning of abnormal results

If the specialist feels that a more accurate evaluation is necessary, they will obtain a biopsy of the lining of the bowel for analysis.

If polyps are found during the procedure, these can be removed straight away.

Are there alternatives to this test?

There is now an alternative to traditional colonoscopy that is much less invasive and does not require sedation. This is called a virtual colonoscopy, which is an examination that uses images of the inside of the bowel and colon obtained by means of computerised tomography (CT or CAT scan) instead of images taken by the colonoscopy camera.