Colonoscopy
A colonoscopy is performed to directly visualise the inside of the bowels. It is the single best investigation for screening for bowel cancer and preventing bowel cancer. In performing a colonoscopy, your doctor can diagnose early cancers and thereby dramatically increase the chance of a cure, remove early growths endoscopically possibly avoiding surgery, as well as removing pre-cancerous polyps and thus prevent cancers from forming. Colonoscopy may be used to diagnose and monitor some chronic inflammatory bowel conditions such as Crohn’s disease or ulcerative colitis. Colonoscopy is also performed for diagnostic purposes in patients with conditions such as anaemia, diarrhoea, or unexplained weight loss.
How to prepare: The key to a successful colonoscopy is in the bowel preparation which is required to clean out the faecal matter in the colon. The bowel preparation starts with ensuring you are very well hydrated in the days leading up to your procedure. You will be asked to commence a specific diet eliminating seeds and nuts, and then fibre in these pre-procedure days. The day before your procedure, you will commence a diet of clear fluids only: no solid food, only liquids that you can see through such as water, soft drink, cordial, black tea and coffee. Your doctor will likely use a “split prep” meaning that you will take the prep in two separate doses. The preparation you will be advised to take will depend on your general health, the condition of your bowel, how you reacted to preparations previously and other medical factors. Take the preparation as you have been advised by your doctor or nurse, drink plenty of liquid in additon to the prep: it is crucial to the success of the colonoscopy and its safety. Continue to drink water up until 2 hours before your scheduled procedure time.
Most colonoscopies are performed as day procedures, meaning you will go home that same day. You will need someone to drop you and pick you up as you cannot drive on the day of your procedure due to the sedatives used, even if you are not tired. Wear comfortable clothing. Bring your medication with you. Your doctor will advise you as to whether or not you need to stop any medication before the procedure.
What to expect: Upon arrival you will be admitted and have observations taken. You may be asked to change into a hospital gown. Your doctors will speak with you before your procedure: ask any last minute questions, voice any concerns. An intravenous canula will be placed in your arm and monitoring equipment will be applied. You will be given oxygen by mask. A mild sedative will be infused prior to the procedure. During the procedure, the colonoscope will be passed into the bowel with the aim of visualising the entire large intestine or colon. The colonscope is inserted as far as possible along your large and then small bowel, limited by preparation, length of the instrument and safety and tolerence. Your doctor may use blue dye spray along the colon to identify flat polyps that can be difficult to see, you may pass some of this dye in your stool subsequently. Biopsies, tiny pieces of tissue, may be taken for microscopic analysis. If polyps are found, it is likely your doctor will remove them during the procedure. If potentially bleeding vessels are found, your doctor may cauterise them or clip them. These clips will fall off on their own in subsequent weeks.
After the procedure: You will be taken to recovery and given refreshments when you are awake. Most patients do not remember the procedure, feel well rested and comfortable on waking. It is not unusual to have woken up during the procedure as only a mild sedative is used. Some patients experience abdominal cramping afterwards which responds to paracetamol and hot packs. Your doctor will see you before you go home to ensure you are well and to explain the results of the procedure. You will be given a written preliminary report (usually with pictures) to take with you. You may need an appointment to discuss pathology findings a few weeks later. Your bowels will return to normal within a day or so of the procedure.
Complications: Colonoscopy is a safe procedure and complications are rare in experienced hands, in well-equiped centres. The main risks are of the bowel bleeding from biopsy or polypectomy sites, or tearing. These complications can usually be managed at endoscopy but rarely, they can require surgery to fix. Up to 10 days post polypectomy, you have some risk of bleeding from the site. Avoid heavy lifting and strenuous exercise during this time if significant lesions have been removed. If you experience temperatures, abdominal pain, noticabale volumes of blood loss in the stool, contact your doctor or nurse immediately or present to the nearest emergency department.
