What is it?

Colonoscopy is a procedure that allows the doctor to look inside the large bowel or colon. A flexible tube with a light and a camera (the colonoscope) is inserted into the colon via the rectum and the doctor can examine the lining of the large bowel.


When is it indicated?

A colonoscopy will be recommended if

  • You have rectal bleeding
  • You have a family history of bowel cancer
  • You have other unexplained abdominal pain



What does it involve?

Colonoscopy is an examination of the whole large bowel by a long fibreoptic tube (the colonoscope) which is passed through the back passage. This tube is connected to a camera, which can see around corners. A very bright light shows the bowel lining clearly.

It is necessary for the bowel to be empty before the test so that the doctor can see the lining of the bowel clearly. To do this effectively you will be asked to drink a bowel cleansing medicine the day before the test and to take only clear fluids for 24 hours beforehand.


Although not particularly pleasant, it is very important for you to follow the instructions as otherwise the doctor will not be able to perform the test effectively and it will have to be repeated. The procedure is done as a day case and patients are usually admitted on the morning of the procedure.


The doctor will give a sedative injection and patients have no memory or pain from the test. The test generally takes about 25 minutes.