A colonoscopy involves a thin, flexible tube with a light and camera at the end being gently inserted by an experienced specialist into the colon via the anus.
Images captured by the camera are relayed simultaneously onto a screen, enabling the specialist to closely examine the inside of the colon walls and rectum.
There are a number of reasons why a colonoscopy may be required, including symptoms such as persistent diarrhoea or constipation, bleeding from the rectum or blood in the stools and abdominal pain, plus any significant changes in bowel habits in older age groups that may be cause for investigation. It can also be useful for monitoring changes in people already diagnosed with digestive disorders, such as inflammatory bowel disease.
You’ll be asked not to eat anything for a certain number of hours beforehand and may be given medication (or an enema if necessary) to help clear the bowels, in order to maximise the effectiveness of the procedure. You’ll be asked to change into a gown and lie on your side while the procedure takes place. It shouldn’t be painful but might feel slightly uncomfortable. Taking a painkiller beforehand can help ensure you’re as comfortable and relaxed as possible – but if you are anxious the best thing to do is tell us, as sedation may be an option.
Some air will be gently pumped into your bowels, to enable the specialist to get a clearer look. This will pass naturally during the following 24 hours or so. You’ll be able to go home shortly afterwards and should be able to carry on with all regular daily activities from the next day (although if sedation was used, you’ll need somebody to accompany you home and won’t be able to drive or operate machinery for 24 hours).
Sometimes, additional procedures and treatments can be carried out during the colonoscopy, such as removing tissue samples for lab testing (biopsies). If polyps are detected (growths on the bowel walls), a specialist will often be able to remove them during the colonoscopy too. These may then be sent to the labs for testing and you may experience some mild pain and bleeding afterwards, but this should ease within a day or two.