A colonoscopy is an important and accurate way of investigating a range of gastrointestinal symptoms including diarrhoea, blood in the stool, or anaemia. The procedure involves the insertion of a thin flexible telescope (colonoscope) into the back passage (anus) , and around the colon to the caecum. It can detect or rule out various causes of these symptoms, including polyps, tumours or inflammation in the colon. As well as providing further diagnostic information about your condition, treatment may also be carried out, including the removal of polyps, treatment of areas that may be bleeding, and occasionally the treatment of narrowings (strictures) in the bowel.

Before and after a colonoscopy

• Colonoscopy is a very safe procedure, with bleeding or a perforation of the bowel very rarely occurring. However, like all medical procedures it is not entirely free from risk. Potential risks will be explained to you beforehand when you give consent for the procedure, but please feel able to discuss your concerns at any point prior to colonoscopy.
• If you are taking blood thinning medications such as aspirin, clopidogrel or warfarin, this may prevent us performing some procedures during a colonoscopy. Please tell your gastroenterologist if you are taking these drugs, as you may need to stop taking them or adjust your dose up to one week before your procedure.
• Your bowel must be empty, so you will not be able to eat for at least 12 hours before your procedure, and you will be given a strong laxative to take the day before.
• You can drink clear liquids (tea/coffee with no milk, or water) up to two hours before.
• If you are having a light sedative, it is important to arrange for a friend or relative to take you home afterwards, as you will not be able to drive; you are strongly advised not to go home unaccompanied.
• If you have received sedation you are advised not to return to work or take part in complex or strenuous activities on the day of the procedure, but you will be fine to do so the following day.

The colonoscopy procedure

A colonoscopy is performed as an outpatient procedure, often using a light sedative. You will be asked to dress in a hospital gown, and a thin cannula will be inserted into a vein in your hand or arm; this will be used to give sedatives into the blood stream. Once in the endoscopy room, you will be asked to lie on your left hand side and to then draw your knees up to your abdomen. Your gastroenterologist will use a colonoscope to perform a careful and detailed examination of the whole of the colon.

A combination of a sedative, painkiller, and muscle relaxant is often given intravenously, prior to the procedure. This will make you feel relaxed but you will still be aware of what is happening and your gastroenterologist will talk to you throughout. The procedure is not pleasant but is rarely painful. Carbon dioxide gas is introduced into the colon to make the images clearer, so you may feel a little bloated but this will soon pass. The results of the procedure will be discussed with you after the procedure.