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Information about Flexible sigmoidoscopy


What is flexible sigmoidoscopy?

Flexible sigmoidoscopy allows inspection of the lining of the anus, rectum and lower part of the colon/large bowel. It uses a flexible tube 10mm wide with a video camera at the tip. Pictures from this camera are seen on a television by the endoscopist. This procedure usually takes about 20 minutes and can be done with or without sedation.


Why have a sigmoidoscopy?

Sigmoidoscopy is used to investigate symptoms you may be having such as change in bowel habit, rectal bleeding or to review a problem that has been found before such as polyps or Colitis. A sigmoidoscopy is a straightforward way of examining your lower bowel and therefore is often the first test that your doctor may request when you are experiencing bowel problems. It may however, be necessary to undertake further tests such as colonoscopy or CT scan following this procedure.


How do I prepare for a sigmoidoscopy?

You will be asked to have no food for 6 hours and no drinks for 2 hours before your appointment time. Usually, one or two enemas (a solution that is squeezed into the rectum to clean the lower bowel) is the only preparation and it is given before the procedure. A full bowel clean-out prior may sometimes be needed, requiring bowel cleansing liquids to be consumed before the procedure. We will plan this with you before your appointment if needed. Occasionally your endoscopist may decide not to use any preparation.


Should I continue my current medications?

Most medications can be continued as usual. Inform the department before your appointment using phone number or email below if you are taking blood thinning medications (except aspirin), diabetes medications or iron supplements as these may need to be adjusted.


How is sigmoidoscopy performed?


Before the procedure begins a sedative can be given, although it is not essential and some patients opt not to have sedation. If you do choose to have sedation you will not receive a full general anaesthetic so you will not be completely unconscious. You may be slightly aware of what is going on in the room but generally you won’t remember much. The medications for sedation are given through an IV cannula placed in the vein before the procedure and the endoscopist and nursing staff will monitor your vital signs during the procedure and will try to make you as comfortable as possible.


You will lie on your left side while your endoscopist inserts the endoscope through the anus (bottom) and advances it through the colon. You might experience a feeling of pressure, bloating or cramping during the procedure when the endoscopist introduces carbon dioxide gas into the bowel via the endoscope. This is necessary to see the colon and the gas can usually be relieved by passing wind which you should not feel embarrassed about.

You may be asked to change position during the procedure e.g. roll onto your back to make the procedure easier.

Removal of polyps and biopsies

Polyps are growths from the lining of the colon, and can vary in size and type. Some are perfectly innocent but others can slowly develop into cancer if they are not removed. If your endoscopist finds polyps, they might take a biopsy or remove them then and there, and they may organise a colonoscopy in order to examine the entire colon if there is a concern about more polyps.
Biopsies are used to identify many conditions, so your endoscopist might perform one even if they don’t suspect cancer.


Are there any risks or side effects?

Although complications can occur, they are rare and will be discussed with you prior to the procedure taking place.
  • Having a sigmoidoscopy carries a small risk of making a hole in the bowel wall (perforation) this occurs once in every 1000 examinations. Perforations usually need to be repaired with an operation.
  • If a polyp is removed then the risk of perforation, although still rare increases slightly to 1 in 500 occasions.
  • Bleeding from the back passage can occur, especially if biopsies are taken or polyps removed. Bleeding usually stops without intervention, although occasionally treatment is needed to stop this.
  • Using sedation can affect your breathing. Your breathing is monitored by staff during the procedure. The endoscopist may give you minimal sedation if it is felt that you are at high risk of breathing difficulties during the procedure.
  • Despite sedation some patients experience abdominal discomfort or pain due to the CO2 that is put into the bowel via the endoscope or due to the scope negotiating the natural bends in the bowel. This should decrease when the procedure has ended and will be helped by passing wind.


What happens after flexible sigmoidoscopy?

After the procedure you will remain in the recovery area until the sedation wears off. If you have not had sedation you will be able to go home once you have received your results.
You will usually be given something light to eat or drink once you are awake. You should expect to be with us for approximately 3- 4 hours in total.
Your results will be explained to you when the procedure is done. The result of the biopsies or samples can take 1-2 weeks to be processed so your results can be discussed with you by your GP or specialist.
You might feel bloating or some mild cramping because of the gas that was passed into the colon during the examination. This will disappear quickly once the procedure has finished.


Who can I contact if I have any questions?

You will be given an opportunity to ask questions prior to your procedure when you are being reviewed by the nurses or endoscopist or you can phone or email as below.
If you have any problem understanding or reading any of this information, please contact the Endoscopy Unit staff on 570 9191 or gastroenterology email.