Colonoscopy
What is a Colonoscopy?
A colonoscopy is a type of endocopy which is carried out when a doctor needs to examine your large bowel (large intestine, colon and rectum). A flexible tube about 1cm thick which as a light and camera at one end is passed through the anus and moved around the large bowel to see the lining of the bowel. This is often an outpatient procedure which takes about an hour to complete. After you have recovered from the effects of a sedative, you are usually able to go home.
How is a Colonoscopy performed?
The procedure is carried out by a specialist doctor or nurse called an endoscopist. You will be offered a sedative and painkiller to help you relax and feel comfortable during the procedure. The sedative will make you sleepy but not put you to sleep. You will lie on your side with your knees bent and the doctor will pass the tube up through the anus into the large bowel. First, air will be passed through a channel in the endoscope to expand the bowel and make it easier to see the lining. This may make you feel slightly bloated or need to go to the toilet but you will not be able to as there will not be anything in your bowel. During the procedure you may feel some discomfort when the tube is first inserted and as it moves around your bowel but you should not feel any pain. You may have to move around slightly or a nurse press on your abdomen (tummy) to help move the colonoscopy in the right direction. Sometimes biopsies can be taken by passing instruments through the colonoscope – this is a painless procedure. If there are small growth on the lining of your bowel (polyps) these will be removed. They are usually not cancerous but could become canceorus.
How to prepare for a Colonoscopy?
To make sure the specialist carrying out the procedure has a clear view of your colon, it must be empty. The day before your procedure you can only eat low fibre food such as white bread, jelly, fish and ice cream. On the day of your procedure you will take a laxative to clear your bowel. This can feel like diarrhoea so the day before your procedure you should aim to drink a glass of water every hour to stop you getting too dehydrated. If you are on any medication, you should discuss this when the doctor beforehand and they will tell you whether to continue with those medications the few days before the procedure.
What happens after the procedure?
After the procedure you will be taken to the recovery area. If you have had sedation you will be given time to rest and let the sedative wear off. Someone should escort you home and stay with you for 24 hours, your procedure may be cancelled and rearranged for another time when someone can stay with you. In the first 24 hours after your exam you cannot drive or ride a bicycle or car, operate heavy machinery, drink alcohol, take sleeping tablets, go to work or make important decisions due to the effects of the sedation. If you did not have sedation, you should be able to go home straight away. You may feel bloated after the procedure from the air which was passed into your bowel from your procedure but this should pass easily and quickly.
Colonoscopies are routine procedures with few risks. However, in rare cases there may be a perforated bowel (1/1000) which will need to be repaired surgically. If you have had a polyp removed or a biopsy taken, there is a small risk of bleeding which will usually stop itself.
There are also some low risks with sedation of difficulty breathing or heart problems. You are monitored throughout the procedure and the sedation can be reversed if there is a problem though.
