What is Colonoscopy
Colonoscopy is a very accurate and sensitive test as it allows direct visualisation of the entire large bowel. This is undertake after preparation with laxatives, which you will be given before the procedure with information on how to take them by the Endoscopy Centre team. Additional benefits include the ability to remove polyps and some early cancers during the procedure, and also biopsy any abnormalities for subsequent microscopic examination. Colonoscopy is usually performed under mild sedation, but can be performed without. Large polyps can be removed at the time of the procedure without the need for an operation, preventing them from becoming cancerous. In the USA this is the method of choice for bowel cancer screening.
What can I expect?
In the examination room you will be made comfortable on a couch, lying on your side. The consultant may give you a sedative injection to make you sleepy and relaxed. The consultant will then gently insert a flexible tube (colonoscope) through the anus into the large bowel. The colon will be gently inflated by passing carbon dioxide through it to give a clearer view of the bowel lining. You may get the sensation of wanting to go to the toilet, but as the bowel is empty there is no danger of this happening. the test will usually be completed in less than 25 minutes and a nurse will be with you throughout the test.
Are there any risks?
Colonoscopy is a very safe examination, but very rarely problems can occur. The two most important are:
Perforation – this is a tear in the lining of the colon, which can happen during the test. It may not need treating at all, but it may need repairing with surgery, in which case you would need to stay in hospital.
Bleeding – minor bleeding is of no concern. Substantial bleeding can occur up to 10 days after removal of polyps, but is rare.
If you are concerned please contact your GP, the Endoscopy Centre or your local Accident and Emergency department.
After the Test?
If you have sedation, you will need to rest in our department until you are fully awake which can take up to 2 hours. If you do not have sedation you can leave as soon as you feel ready, and can have a normal day. You may eat and drink when you feel like it. You may feel a little bloated and windy, but this usually settles quite quickly.
If you have had a sedative injection as a part of the test it is essential that someone collects you to take you home. Once home, it is important to rest quietly for the remainder of the day. Sedation lasts longer than you think.
For 24 hours after your test you should not:
- drive a car
- operate machinery
- drink alcohol
The effects of the test and sedation should have worn off by the next day, when most patients are able to resume normal activities.