GENERAL INFORMATION
A colonoscopy is a procedure in which the inside of the entire colon can be looked at with an instrument called a colonoscope. Also, if something abnormal is seen, a small piece of it (a biopsy) can be taken for examination in the pathology laboratory.
THE COLONOSCOPE
The colonoscope is a smooth, flexible, optical instrument about as thick as the tip of your little finger. It has lenses in it as well as a light at its tip that lets the doctor see what is ahead. The colonoscope has several small tunnels in it. One tunnel is used to suck out any mucus that might be in the way. Another tunnel is used to pass a very thin wire with a biting tip at its end that can be used to take a biopsy. The colonoscope is three feet long so that it can be passed up to the very beginning of the large bowel. The end held by the operator has a knob and several buttons that are used to steer the tip of the colonoscope as it is passed up the colon. The buttons are used to control the suction and other functions.
PREPARATION FOR THE COLONOSCOPY
The bowel must be cleansed of all stool so that the lining can be clearly seen. You will be instructed by the doctor how to clean your bowel.
THE COLONOSCOPY PROCEDURE
• A needle will be put into your arm for either an injection or an infusion. This will make you drowsy. The colonoscope will be lubricated thoroughly and inserted gently through
the anus and into the colon. The instrument will be advanced through the entire colon for a thorough examination.
• You will be able to hear and co-operate with the doctor as you are asked to change your position, but you will not be too aware of what is happening.
• When the procedure is completed, the relaxing medicine will be stopped and within a few minutes you will be fully awake.
• The procedure takes approximately 30 minutes. Many patients remember so little of the procedure they think it took just a few minutes, or they may not remember anything at all about it.
• Your blood pressure, pulse and breathing will be watched until they are stable. When you are completely alert, you should be able to go home with a responsible adult. You may not drive yourself or work for the rest of the day.
COMPLICATIONS
• It may not be possible to pass the colonoscope all the way through the large bowel. Your doctor may decide to follow this up with a barium enema.
• Very rarely the colonoscope may perforate the large bowel. In the unlikely event that this happens, you will have to have a laparoscopy/laparotomy to have this perforation repaired.
• If a biopsy is done or a polyp is removed, very infrequently there may be a large bleed.
Your doctor will decide how best to manage this.