What Is A Colonoscopy
A colonoscopy is a test where a consultant looks into your colon. The colon is sometimes known as the large intestine or large bowel. The colon is the part of the gut which comes after the small intestine. The last part of the colon leads into the rectum where faeces (stools or motions) are stored before being passed out from the anus.
A colonoscope is a thin, flexible, telescope. It is passed through the anus and into the colon. It can be pushed all the way round the colon as far as the caecum (where the small and large intestine meet). Another test called sigmoidoscopy looks at the rectum and the lower part of the colon. The colonoscope contains fibre optic channels which allow light to shine down so your consultant can see inside your colon. The colonoscope also has a ‘side channel’ down which devices can pass. These can be manipulated by the consultant. For example, the operator may take a small sample (biopsy) from the inside lining of the colon by using a thin ‘grabbing’ instrument which is passed down a side channel.
Who Has A Colonoscopy?
A colonoscopy may be advised if you have symptoms such as bleeding from the anus, pains in the lower abdomen, persistent diarrhoea, or other symptoms thought to be coming from the colon.
The sort of conditions which can be confirmed include:
- Ulcerative colitis (which causes inflammation of the colon).
- Crohn’s disease (also causes inflammation of the colon).
- Diverticula (pouches which form in the lining of the colon).
- Polyps of the colon.
- Cancer of the colon.
Various other conditions may also be detected. Also, a colonoscopy is often normal. However, a normal result may help to rule out certain possible causes of your symptoms.
What Happens During A Colonoscopy?
Colonoscopy is usually done as an outpatient or day case. It is a routine test which is commonly done. You will usually be given a sedative to help you to relax. This is usually given by an injection into a vein in the back of your hand. The sedative can make you drowsy but it does not ‘put you to sleep’. It is not a general anaesthetic.
You lie on your side on a couch. The operator will gently push the end of the colonoscope into your anus and up into the colon. The operator can look down the colonoscope and inspect the lining of the colon. Also, modern colonoscopes transmit pictures through a camera attachment on to a TV monitor for the operator to look at.
Air is passed down a channel in the colonoscope into the colon to make the inside lining easier to see. This may cause you to feel as if you want to go to the toilet (although there will be no faeces to pass). The air may also make you feel bloated, cause some mild ‘wind pains’, and may cause you to pass wind. This is normal and there is no need to be embarrassed, as the operator will expect this to happen.
The operator may take biopsies (small samples) of some parts of the inside lining of the colon – depending on why the test is done. This is painless. The biopsy samples are sent to the lab for testing, and to look at under the microscope. Also, it is possible to remove polyps, which may be found, with an instrument attached to a colonoscope. (Polyps are small lumps of tissue which hang from the inside lining of the colon.) At the end of the procedure the colonoscope is gently pulled out.
How Long Does A Colonoscopy Take?
A colonoscopy usually takes about 20-30 minutes. However, you should allow at least two hours for the whole appointment to prepare, give time for the sedative to work, for the colonoscopy itself, and to recover. A colonoscopy does not usually hurt, but it can be a little uncomfortable, particularly when the colonoscope is first passed into the anus.
Preparing For A Colonoscopy
You should get instructions from the GI Unit team before your test. The sort of instructions given include:
- The colon needs to be empty so that the operator can get a clear view. You will be instructed on how to take a special diet for a few days before the test. You will also be given some laxatives to take.
- You will need somebody to accompany you home, as you will be drowsy with the sedative.
What Can I Expect After A Colonoscopy?
Most people are ready to go home after resting for half an hour or so. You may need to stay a bit longer for observation if you have had any polyps removed.
If you have had a sedative – you may take a bit longer to be ready to go home. The sedative will normally make you feel quite pleasant and relaxed. However, you should not drive, operate machinery or drink alcohol for 24 hours after having the sedative. You will need somebody to accompany you home and to stay with you for 24 hours until the effects have fully worn off. Most people are able to resume normal activities after 24 hours.
The consultant writes a report and sends it to the doctor who requested the colonoscopy. The result from any biopsy may take a few days which can delay the report being sent.
The operator may also tell you what they saw before you leave. However, if you have had a sedative you may not remember afterwards what they said. Therefore, you may wish to have a relative or close friend with you who may be able to remember what was said.
To ask a question about a colonoscopy or to book an appointment, contact our specialist team available Monday – Friday 8am – 6pm and on Saturday from 9am – 1pm.
Our gastrointestinal specialists team have a dedicated and caring approach and will seek to find you the earliest appointment possible with the correct specialist for your needs. If you are self-paying you don’t need a referral from your GP. You can simply refer yourself and book an appointment. If you have medical insurance (e.g. Bupa, Axa PPP, Aviva), you will need to contact your insurer for authorisation for any treatment and, in most cases, you will require a referral letter from your GP. If you do not have a GP, then we have an in-house private GP practice that you can use.Alternatively we can suggest the most appropriate course of action for you to take, given your location and individual circumstance.