A flexible, telescopic tube camera will be gently passed through your rectum (back passage) and around the loops of your large bowel. As it goes, air will be puffed through the colonoscope to gently inflate your bowel to give a better view. The doctor or nurse will be looking for signs of disease.

A sample of the bowel lining (a biopsy) may be taken for testing. It is possible to remove polyps if they are found. They will be tested too.

There is a slight risk of bowel perforation with this test – ask your doctor to explain. You will be given written information about the risks.

On the day before the test, you will need to take powerful laxatives to completely empty your bowel, to give the doctor a clear view.

The test can be uncomfortable, so when you go to hospital for it, you will be given a sedative injection to make you relaxed. It may make you sleepy too. You may also be given painkillers.

The test lasts 30 to 45 minutes. After the test you will need to rest for one to two hours before leaving.

Someone will have to come and collect you, to take you home. You should not drive yourself.

If your bowel is normal, you should get your results on the day of the examination. If a biopsy has been taken, or a polyp removed (a polypectomy) you may be called back to the hospital to discuss the results, or you may go to your own GP's surgery for the results.