What is a colonoscopy?

Colonoscopy is the examination of the large bowel (colon) with a flexible instrument (colonoscope). The colonoscope has a video chip camera at its tip which enables direct visualization of the colon. Instruments can be passed down the colonoscope to take samples of the colon (biopsies) or to remove growths (polyps) from the colon. The colonoscope is inserted through the anus, under sedation, and will travel approximately 1 metre to the end of the large bowel. This procedure usually takes 20 to 30 minutes.


Why have a colonoscopy?

Colonoscopies are usually performed for bowel symptom such as diarrhoea, pain and bleeding. In some people with a family history of bowel cancer, colonoscopy may be an appropriate test for screen for this cancer. Other alternative tests do exist for examining the colon such as barium enema and virtual CT colonoscopy and may be appropriate in some situations. However, these tests are less sensitive and do not enable biopsies or removal of polyps.


Will I be awake and does it hurt?

All procedures at Ashford, Wakefield and Glenelg Community Hospital are assisted by an anaesthetist. The anaesthetist will provide you with deep sedation so you should not experience pain or discomfort during the colonoscopy. After the procedure you may experience some windy discomfort due to gas used to inflate the colon during the procedure. This should be short lived but if it persists and you are concerned please contact Dr Wigg, via his rooms.


Why do I need a bowel preparation?

Preparing the bowel is often the most difficult part of the process for patients. However, a good bowel preparation is essential for a successful colonoscopy. You will collect the appropriate prep kit and will need to follow the instructions, found inside the kit, very carefully. It is important to remember that you will be drinking clear fluids only after a light lunch the day before your procedure and you must drink plenty of these clear fluids during the preparation to avoid dehydration. If you are on diabetic or blood thinning medication you will receive instructions about managing these.


Is the procedure safe and what are the risks?

Colonoscopy is a very safe and routine procedure. However, all procedures have risks which are detailed below.

  1. Incomplete colonoscopy– in about 5 % of cases the colonoscope is unable to be passed to the end of the large bowel. If this does occur and it is felt necessary to examine the entire colon then a barium enema or virtual CT colonoscopy will be arranged, on the same day if possible.
  2. Missed lesionsalthough colonoscopy is the most accurate bowel test it can occasionally miss important lesions in the bowel such as large polyps or cancers. The miss rate for such lesions is somewhere in the region of 2 to 8 %. For this reason it is recommended that you continue to test your faeces for blood every 1 to 2 years if you are over 50 years, despite having a normal colonoscopy.
  3. Perforationa perforation of the bowel occurs when a tear is made by the colonoscope. This is rare, about 1 in every 1000 colonoscopies. Risk factors include elderly patients with severe diverticulosis and extensive prior abdominal or pelvis surgery. If this does occur usually an operation is required which would involve a stay in hospital for a week.
  4. Bleedingpassage of small amounts of blood following biopsies or polyp removal during colonoscopy is not uncommon. In about 1 in 100 cases following polyp removal the bleeding may be severe enough to need a blood transfusion.


What should I bring with me on the day?

You will be in the hospital for several hours so bring some reading material to pass the time. Please bring a list of your medications.


What happens after my colonoscopy? After the procedure you will be taken to a recovery room and monitored until you recover from the anaesthetic. You will be given light refreshments prior to discharge. Dr Wigg will discuss the results of the procedure with you and make follow up arrangements if required.   Driving is not permitted for the remainder of the day and you must make arrangements for a responsible adult to pick you up and remain with you until the following day.


What will the cost be to me? For patients with private health insurance Dr Wigg nor his anaesthetist charge an out of pocket gap. The only expense you may have is if your private cover has an excess. Uninsured patients will be provided with a quotation of costs at the time of booking the procedure.