The Leeds Teaching Hospitals NHS Trust


What is a Colonoscopy?

Colonoscopy is performed to examine the entire colon (bowel). The flexible endoscope is passed through the anus around the colon as far as the junction with the small bowel. Sometimes the endoscope is passed into the end part of the small intestine. It takes approximately 20-30 minutes to do the procedure.

Colonoscopy is commonly performed to examine symptoms including change of bowel habit, bleeding or monitoring of pre-existing conditions such as polyps. You may be referred by your hospital consultant or directly by your GP but it is an extremely common procedure to be performed.

colon2You may also be referred following a positive stool blood test (FOB) as part of the national bowel cancer screening programme

Preparing for the procedure

Prior to the procedure you will have been asked to take some bowel preparation, or strong laxatives, to clean the bowel. You must take the bowel preparation that has been sent to you as instructed to ensure that your bowel is clean so that the endoscopist can see the bowel lining clearly. Failure to take the bowel prep correctly may mean that you have to have the procedure again at a later date.

During the procedure

The main discomfort during the procedure occurs from the stretching of the bowel from the gas used to inflate it, or stretching of the wall from the passage of the colonoscope. We try to keep the amount of gas that we put into the bowel to a minimum to avoid causing you discomfort but we have to put some air in so we can see where to pass the colonoscope.

You may notice a piece of equipment that stands in front of your bed, this is a called scope guide. It helps the endoscopist to see if there is looping or twisting of the colonoscope in your bowel. This can help the endoscopist to keep discomfort to a minimum for you as the bowel is stretched less.

During a colonoscopy, if the endoscopist finds a polyp they may remove it unless it is too large. Whilst all procedures carry risks, the chance of a major complication occurring in a colonoscopy is small.

Pain relief 

To further reduce the discomfort during their colonoscopy, some patients choose to have Entonox (gas and air) whereas others prefer to have an injection with a painkiller and sedation. Some patients are happy to have the procedure without any pain relief. The patient information leaflet below has details about the options available to you for pain relief during your colonoscopy.

After the procedure

Following your colonoscopy, you will be discharged from the department the same day. If you have sedation you will need to recover in the unit for a few hours after.  You will also need someone to collect you from the endoscopy unit and take you home (not on public transport) and someone to stay with you for 24 hours. You will also not be able to work, drive a car or operate machinery for 24 hours.

Before you leave the endoscopy unit the nurses will give you advice about what to expect after your test and a contact number in case you experience any problems.

Download more information

For further information please read our patient information leaflets: