Flexible Sigmoidoscopy

Flexible Sigmoidoscopy

What is a Flexible Sigmoidoscopy?

Flexible Sigmoidoscopy is a procedure used to examine or inspect the inside surface of the rectum and lower large bowel (Sigmoid Colon). This examination is performed using a Colonoscope. This then allows for a variety of therapeutic procedures to be performed through the Colonoscope if required. Such procedures may include biopsy and removal of polyps.

How are you prepared?

You must not have any food for six (6) hours before your procedure, you may drink water up until three (3) hours before your procedure - then you will be fasting (no food,no fluid, no smoking).

Prior to the procedure you will be provided with a kit containing full instructions for your preparation. Two hours prior to your procedure you are required to have 2 small Microlax Enemas to empty the lower end of you large bowel and rectum. This will be something you will need to self-administer at home before you arrive.

Flexible Sigmoidoscopy is usually performed without the need for sedation. However, occasionally sedation is required and therefore you should have a responsible adult with you to drive you home in this event.

What we do

The colonoscope is a long highly flexible tube about the thickness of your index finger. It is inserted through the rectum and allows inspection of the lower large bowel. As colon cancer arises from pre-existing polyps (benign tumours), it is advisable that if any polyps are found, they be removed at the time of examination. Most polyps can be burnt off by placing a wire snare around the base and applying an electric current.


You will be given time to recover from your procedure in an observed recovery area, during which time you will be given a drink with biscuits.

The doctor will:

  • Talk with you and discuss his findings
  • Give you a hand written report regarding your procedure and any follow up instructions
  • Send a detailed report to your doctor

For legal reasons you must not drive a vehicle or operate machinery for at least 12 hours following sedation. Driving under the influence of sedation carries the same implications as with alcohol. You should have a responsible adult with you to drive you home and stay with you for twelve hours.

Risks and complications

For inspection of the bowel alone, complications of Flexible Sigmoidoscopy are very uncommon. Most surveys report complications of 1:1000 examinations or less.

Complications that can occur include an intolerance of the bowel preparation enemas or reaction to the sedative used (if required for the procedure). Perforation (making a hole in bowel) or major bleeding from the bowel is extremely rare, but if it occurs may require surgery.

When interventions, such as removal of polyps, are carried out at the time of procedure there is a slightly higher risk of perforation or bleeding from the site where the polyp was removed.

A number of rare side-effects can occur with any endoscopic procedure. If you wish to have full details of such complications explained to you please discuss this with the doctor prior to the examination.

Because of the risk of cancer, it is recommended that all polyps found be removed at the time of your procedure. If you require sedation, it will not be possible to discuss the removal at the time, therefore if you have any queries regarding polyp removal please discuss this prior to the procedure. In the unlikely event of haemorrhage occurring, blood transfusion may be necessary.