A colonoscopy is a procedure which uses an endoscope (a flexible narrow tube) which can be guided round the lower bowel, also called the colon or large intestine.
Why Why do I need a Colonoscopy?
Your doctor will have advised that you should have your large bowel inspected to investigate symptoms such as, altered bowel habits, abdominal pain, rectal bleeding, anemia or if if you family H/O of colon cancer or polyps. Specimens of the bowel wall can be taken for inspection in the laboratory. Polyps can also be removed with the colonoscope (see below).
What preparation will I need?
The colon needs to be totally empty so that the doctor can see it clearly. You will be sent laxative preparation to clean out your bowel along with instructions. You should read and follow the instructions carefully. You will be helping to make sure the examination goes well.
Dietary advice before procedure
What does the procedure involve?
You will be required to wear a patient gown having removed most of your own clothing. In addition, if you have a lightweight dressing gown and you prefer to wear your own then you are welcome to bring it with you. You can put your belongings in a basket which will stay with you throughout your stay in the unit. Once changed you will go into another room where the doctor will ask you to sign a consent form which gives him/her your permission to perform the test. You will be asked to lie on your left side by the nurse who will be looking after you. Any dentures, particularly loose fitting ones, should be removed at this time. You will be covered by a sheet at all times. During this procedure we will record your pulse rate and your oxygen levels. Your blood pressure will also be monitored on a clip attached to your finger.
During the test we will be giving you some oxygen through a small tube just inside your nose.
This is all routine and perfectly normal.
Will the test hurt?
We always give you (painkillers and mild sedative) to make you relaxed and sleepy as well as something to relieve discomfort. These drugs are given by injection through a tiny plastic tube placed into a vein in your arm or hand. Most patients remember little of the procedure, wake up shortly afterwards and can go home about one hour later.
What are the risks, side effects and complications?
Colonoscopy is a very safe procedure and complications are rare. When polyps (growth of lining of bowel) are found they must be removed to prevent progression to cancer and to allow examination under the microscope. These polyps can be removed during the procedure with the help of a snare passed down the colonoscope. This can cause bleeding from the polyp base but we can usually stop this quite easily. Only rarely is blood transfusion or surgery needed. Even more rarely does bowel perforation occur but if it does it may require surgical repair. Some patients experience mild discomfort due to wind after the test Ė this goes rapidly after the test.
The risk of dying as a result of a Colonoscopy is less than 1 in 1000. The sedation we use is also remarkably safe with few side effects afterwards. However, you will not be allowed to drive or operate machinery for the next 24 hours. You will also need to be with an adult for the next 24 hours.
Will I have to stay in Hospital?
This is a day case procedure for most patients. You may require overnight observation if it is felt that you are at risk of bleeding, perforation or excessive sedation.
When will I hear my results?
You or your accompanying relative or friend will be told the results before you go home. Some further information from the laboratory may not be available for a week or two and will be forwarded to your GP or given to you at your next Clinic visit.
Finally, we will do our best to make your colonoscopy as comfortable and safe as possible.
What are the alternatives to a Colonoscopy?
A barium enema is sometimes used instead of Colonoscopy. It isnít as good as a colonoscopy at spotting cancer, but it is safe. Barium enema is sometimes not as good as Colonoscopy in picking up small polyp or abnormality of lining of bowel.
Newer techniques include the use of scanners (CT and MRI) which may be preferable to a barium enema but not as good as colonoscopy in picking up small polyps. Additionally it doesnt permit simultaneous treatment of polyps or biopsies.
Sigmoidoscopy is another test to look inside your bowel, it is like a colonoscopy, but uses a shorter tube and you donít need to clean out your bowel before a sigmoidoscopy. It is useful only for looking inside your rectum and the lowest part of your colon, (called the sigmoid colon). This test finds between up to two-thirds of polyps and cancers.
If you are still unclear or worried about your endoscopic examination please contact your doctor.