What is a Colonoscopy?
Colonoscopy is the examination of the large bowel (colon), which is the last portion of the digestive tract, with a flexible instrument (Colonoscope). The adjustable controls and tiny video camera at its tip allow the Doctor to carefully guide the instrument and obtained detailed views of the inside lining of the colon. Other instruments can be passed through the Colonoscope to take small samples of tissue (biopsies) for further analysis or to remove polyps.
Colonoscopies are most commonly performed for bowel symptoms such as diarrhoea, pain or bleeding. It is also performed to screen for bowel cancer or polyps.
How to prepare for a Colonoscopy?
For a successful colonoscopy, the bowel must be well prepared. Before colonoscopy, your doctor/nurse will tell you what you can and cannot eat and drink. They will also tell you what bowel cleansing routine to use. The preparation is usually made up of either a special cleansing drink or oral laxatives. Be sure to follow the instructions carefully.
Can I continue taking my usual medications?
You should be able to carry on taking your usual medications, but some medications may cause problems with the examination. You must tell your doctor/nurse what you are taking, particularly:
- Arthritis drugs
- Antiplatelet drugs e.g. Plavix/Iscover
- Blood thinners e.g. Warfarin (anticoagulants)
- Diabetic tablets or Insulin
- Iron supplements
- Any herbal remedies
What can you expect after a Colonoscopy?
You will be cared for until most of the effects of the medications have worn off.
You will be given instructions regarding how soon you can eat and drink and guidelines for resuming your normal routine.
Your doctor will explain the results of the examination and will inform you of any follow up you require either in his rooms or with your general practitioner.
Occasionally minor problems may persist such bloating or cramping however these should disappear in approximately 24 hours.
What must I do to stay safe?
For your safety you must:
- Be taken home by a responsible person
- Have a responsible adult care for you that day/night or be on hand in case of any problems
- Not drive a car or motorcycle (this is against the law) or operate machinery until the following day (12 hours) or for as long as your doctor or sedationist advises.
- Not make any important decisions or sign any contracts within 12 hours of the procedure (the medication used may impair judgement)
- Not drink any alcohol for 12 hours post procedure
- Not participate in strenuous activities for 12 hours
You must also tell the doctor, and if you have:
- any allergies to any drugs
- a pacemaker, a heart valve replacement
- a joint replacement
- severe heart, lung or kidney disease
Tell your doctor if you have to take antibiotics before dental treatment. If so, you may also need antibiotics before a colonoscopy.
Am I awake for this procedure?
During the procedure everything will be done to ensure your comfort. Just before the procedure, you will be given sedation (medication to make you very drowsy and relaxed). This is given through an intravenous line that will be inserted into your arm. You will be able to breathe for yourself and you may have difficulty remembering the experience.
Once you are fully sedated your doctor slowly passes the Colonoscope along your large intestine to carefully view the lining. As you will be sedated you will not be aware of the examination or if biopsies are taken or polyps removed. You should plan on two to three hours for waiting, preparation and recovery. The time needed for colonoscopy will vary, but on average, the procedure itself usually takes approximately 30 minutes.
What are polyps and why are they removed?
Polyps are abnormal growths in the bowel lining, and can vary in size and shape. They can be as small as a tiny dot or up to several centimetres big. While most are not cancerous they may turn into cancer over time. Removing polyps is an important means of preventing bowel cancer. The doctor can remove most polyps through the Colonoscope. This is not painful.
What are the possible complications of colonoscopy?
There are some risks and complications, which can occur. Serious complications are uncommon. These include:
- Perforation (puncture) of the bowel can occur in approximately 1 patient in 2000, often after the removal of large polyps. Should this occur surgery is sometimes required.
- Bleeding from the bowel may follow after removal of polyps. The risk may be greater, the larger the polyp. Sometimes bleeding can happen up to 12 days afterwards. This usually settles without further treatment. Rarely, a blood transfusion and further surgery may be needed if there is a lot of bleeding.
- Reaction or sensitivity to medication used for sedation
- The procedure may not be able to be completed due to bowel disease or other problems.
- Polyps or cancer can be missed. The risks are higher if your bowel is not cleaned properly. It is important that you follow the instructions to clear your bowel before the procedure.
- Mild pain and discomfort in the abdomen for one or two days after the procedure. It usually settles without further treatment.
- Very rarely, heart and lung problems occur, such as: low oxygen levels, lowered blood pressure, higher pulse rate, pneumonia (caused by inhalation of vomit while under sedation).
- Death due to complications of colonoscopy is extremely rare.