Flexible sigmoidoscopy is a frequently performed test to investigate the lower part of the bowel. This is an endoscopic test that allows the consultant to look directly at the lining of the bowel.
Flexible sigmoidoscopy can detect inflammatory bowel disease, polyps and cancers. The procedure is used to help doctors diagnose unexplained changes in bowel habits (for example constipation or diarrhoea), abdominal pain, bleeding, and weight loss. Biopsies can also be taken during the procedure and polyps can be removed.
Do I need any preparation before-hand?
You will receive written instructions about the test beforehand. If you are having sedation or an anaesthetic for the procedure you will instructed to stop eating and drinking beforehand, it is important that you adhere strictly to these instructions. You will normally be given an enema to clear out the lower part of the bowel about 60 minutes before the procedure.
What does the test involve?
The instrument used during this investigation is called a flexible sigmoidoscope. This is a long flexible tube with a light at the end. It is passed through the anus. This allows the doctor to see images of the inside of your bowel on a screen. If you are awake for the procedure you can ask to watch as well if you wish. The doctor may ask you to move periodically so the scope can be adjusted for better viewing.
The doctor can remove growths, called polyps during flexible sigmoidoscopy using special tools passed through the scope. During a flexible sigmoidoscopy, the doctor can also take samples of tissue called biopsies from normal and abnormal-looking tissues.
What are the possible risks?
Flexible sigmoidoscopy is commonly performed and generally safe and complications are rare. Flexible sigmoidoscopy carries a very small risk of perforation (tear) of the bowel. If polyps are removed or biopsies taken bleeding may occur from the site. This is usually minor and may stop on its own or require treatment using a heat probe or injection through the sigmoidoscope. Side effects from sedatives (if given) are rare. These can include problems with your breathing, blood pressure and heart rate. These are usually short lived and quickly treated.
Sometimes it may not be possible to complete your procedure successfully and it may need to be done again. If you develop severe pain or persistent bleeding after you have gone home you should contact the hospital, your own GP or your local A&E department immediately, for further advice.
What happens afterwards?
A flexible sigmoidoscopy takes about 20 minutes to complete. You may feel bloated and have some wind-like pains. These usually settle very quickly. If you have had sedation or an anaesthetic for the procedure you will need to recover fully before going home (please refer to our advice sheet for more information).
The consultant will be able to tell you the result straight after the procedure. The pathologist will process any tissue samples taken and the results will be available within a few days.