A colonoscopy is a test that allows your doctor to look inside your large bowel. It is carried out using a long, narrow and flexible telescopic camera called a colonoscope. Your doctor will pass the colonoscope into your bowel through your anus (back passage).



The procedure usually takes 30 to 45 minutes to complete. Your nurse will ask you to put on a hospital gown that opens at the back (or a gown and trousers that have a hole cut in the back).


You will be asked to wear a mask or have small tubes placed just under your nostrils through which oxygen is passed. You will have a small needle, (Cannula), inserted into a vein in the back of your hand to give you any medicines you may need. You will probably be given a sedative and a painkiller to make sure that you are relaxed and comfortable during the procedure. The sedation will not send you to sleep and you will remain awake during the examination

Your doctor will ask you to lie on your left-hand side and he/she will gently insert the colonoscope into your rectum. Lubricating jelly will be used to make this as easy as possible.


Air will be pumped into your bowel to make it expand slightly, which makes the colonoscope pass through more easily. This might feel uncomfortable and you may pass some wind. Your doctor will gently move the colonoscope up through your bowel. The colonoscope is flexible and the doctor can rotate the tip of the instrument so that it follows the curves in your bowel.


The images from the camera at the end of the colonoscope appear on a monitor – these enable your doctor to look at the inside of your bowel. During the procedure you may be asked to change your position – for example turning from your side on to your back. This will help your doctor to look at different areas of your bowel. He/she may press on your abdomen to help move the colonoscope in the right direction.


During the procedure your doctor may take a biopsy or remove small polyps. This is quick and painless and is done by passing instruments inside the colonoscope. The samples will then be sent to a laboratory for testing to see if the cells are benign or malignant (cancerous).



At the hospital after your colonoscopy, your doctor may discuss any findings from the test with you before you leave, or you may be given a date for a follow-up appointment. If you have had a biopsy or had polyps removed, your results will be sent to the doctor who referred you for the colonoscopy.


Recovering from a colonoscopy - you will need to rest until the effects of the sedative have passed and you will usually be able to go home when you feel ready but, you will need to arrange for someone to drive you home as you are likely to still feel drowsy after the sedative. Try to have a friend or relative stay with you for the first 12 hours after your colonoscopy.


If you need pain relief, you can take over-the-counter medicines, such as paracetamol or ibuprofen. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.


Sedation can temporarily affect your co-ordination and reasoning, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you are in any doubt about driving, contact your motor insurer so that you are aware of their recommendations, and always follow your doctor’s advice.


Most people have no problems after a colonoscopy, but you should contact your GP or the hospital department if you:



Have heavy bleeding from your back passage.


Have a swollen abdomen and abdominal pain that gets worse          and develops into breathlessness or shoulder pain.


Feeling unwell or develop a fever.


As with every procedure, there are some risks associated with colonoscopy. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your doctor to explain how these risks may apply to you. 



These are the unwanted (but mostly temporary) effects you may get after having the procedure.


After having a colonoscopy, you may feel bloated and uncomfortable for a few hours as a result of trapped wind. You may find that lying on your front can help. You may also bleed a little from your back passage, especially if you have had a biopsy or polyp removed.



Complications are when problems occur during or after the procedure. The main ones related to colonoscopy are listed below:


Your doctor may not be able to see your entire bowel. This can happen if your bowel isn’t empty or the colonoscope can’t be passed round a curve. If this happens, you may need to have the colonoscopy done again or have other tests.


Rarely the sedation can affect breathing or your heart. You will be monitored throughout the procedure and treated quickly if this develops.


The colonoscope and the other instruments used during the procedure may damage or tear your bowel. If this happens, you may need an operation to repair it.


You may have heavy bleeding if you have had biopsies or polyps removed. Always keep the advice card handy that the unit will give you in case further advice is required when you are home. This will contain important phone numbers should you have any issues and need to contact them.



Written by Tracy Smith, LSUK Trustee

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