Colonoscopy

A colonoscopy is a procedure that involves the use of a long thin (thickness of your index finger) flexible tube with a small camera at the end (endoscope) to look at the inside of your large bowel. Colonoscopy is used to investigate symptoms such as a change in the bowel habit, anaemia, bleeding from the back passage, abdominal pain and weight loss. It is also used to monitor conditions such as colitis (inflammation of the bowel), to investigate abnormalities seen on x-rays or a positive bowel cancer stool test, to screen families with strong family history of bowel cancer or to monitor patients after surgery for bowel cancer.

Benefits of colonoscopy

The benefit of colonoscopy is that biopsies (small pieces of tissue) can be taken if any problem is found. In addition, any polyps found can be removed during the procedure while the general condition of the lining of the bowel can be directly assessed.

Before the procedure

Prior to the procedure if you are taking any iron tablets you will need to stop them. Similarly if you are on any blood thinning medication such as warfarin or clopidogrel let your doctor know at least 7 days prior to the procedure. It is also important to let your doctor know if you have any significant health problems, have a pacemaker or any medication allergies. You will be given information on following a special diet and when to use some strong laxatives to empty your bowel 24 hours prior to your procedure. These may make you feel slightly sick but they are needed in order to ensure that the bowel is clean and your doctor can have good views of your bowel lining.

The procedure

On the day of the endoscopy a small tube (cannula) will be placed in one of your veins in order to give you some painkillers and a sedative to make you more relaxed and the procedure more comfortable. Alternatively, you can use some gas and air (Entonox). Lying on your side, you will be given the sedation and painkillers through the cannula and the procedure starts. The endoscope is passed through the back passage around the bowel after it is inflated with some gas which may give you a bloating sensation. On occasions your body position may be changed in order to negotiate the various angles of your bowel with the scope. Photographs of the bowel will be taken as well as any required biopsies while any polyps will be removed. The procedure usually lasts 30 to 45min, sometimes longer depending on any treatments required.

Recovery

After the procedure you will be taken to the recovery room. Once you are more awake you will be given something to eat and drink prior to being discharged home. You may feel bloated for a few hours. You will be informed of any follow-up arrangements in anticipation of any results from biopsies. If you elect to have some sedation you will not be able to drive for 24 hours, you need to avoid alcohol and signing any important legal documents and need to ensure that a responsible person will be with you for at least 12 hours.

Risks of the procedure

Colonoscopy is generally a very safe procedure. Complications occur rarely and include the risk of bleeding (less than 1 in 1000 if no polyp is removed, 1 in 50 if a polyp is removed), perforation or tear through the bowel wall that may require surgery (less than 1 in 2500 if no polyp is removed, 1 in 500 if a polyp is removed), rare medication allergies and risk of heart attack or breathing difficulties. In less than 1 in 20 procedures the procedure may not be completed due to technical difficulties, blockage of your bowel or discomfort. Alternative investigations will then be discussed with you and arranged accordingly.