What is Colonoscopy
Colonoscopy is a procedure used to examine or inspect the bowel and allow for procedures to be carried out through the colonscope. These procedures may include taking small tissue samples (biopsy) and removal of polyps. An alternative method of examining the large bowel is a barium enema. Colonoscopy has the advantage over barium enema in that it is more accurate and allows biopsies and removal of polyps at the same time.
How are you prepared
Prior to the colonoscopy, you will be provided with a preparation kit containing full instructions. For a few days before the procedure, you will need to follow a Low Residue Diet. The night before, you will need to take laxatives and on that evening or morning of the procedure, you will need to drink a quantity of salty tasting solution which completely cleanses the colon.
You will be given sedation via a vein in the arm during the procedure to make you more comfortable and usually these drugs are administered by an anaesthetist.
Uncommonly, x-ray screening is used during the procedure. Therefore female patients should advise the nursing staff if there is any possibility of pregnancy.
You should advise the nursing staff if you are sensitive(allergic) to any drug or other substance.
You should cease iron tablets and drugs to stop diarrhoea four days before the procedure. It is also desirable that you are not taking Aspirin or N.S.A.I..D’s (arthritis tablets). If you are on these medications, you should discuss the matter with your doctor. You should also inform your doctor if you are taking blooding thinning tablets, have heart valve disease or have a pacemaker implanted. The effect of the oral contraceptive may by lost as a result of the bowel preparation.
What do we do ?
The colonoscope is a long and highly flexible tube about the thickness of your index finger. It is inserted through the rectum into the large intestine to allow inspection of the whole of the large bowel.
As a cancer of the large bowel arises from the pre-existing polyps (a benign wart-like growth) it is advisable that if any polyps are found they should be removed at the time of the examination. Most polyps can be burnt off (Polypectomy) by placing a wire snare around the base and applying an electric current.
Safety and Risks
Serious complications of colonoscopy are uncommon. Most surveys report complications in 1 in 1,000 examinations or less.
Complication which can occur include intolerance to the bowel preparation solution or reaction to the sedatives used. Perforation (making a hole in the bowel) or major bleeding from the bowel is extremely rare but if it occurs may require surgery.
When procedure such as removals of polyps are carried out at the time of the examination there is a slightly higher risk of perforation or bleeding from the site where the polyp has been removed.
Complications of sedation are uncommon and are usually avoided by administrating oxygen during the procedure and monitoring oxygen levels in the blood. Rarely however in patients with severe cardiac or chest disease, serious sedation reactions can occur.
A number of rare side effects can occur with any endoscopy procedure. Death is a remote possibility with any interventional procedure. If you wish to have full details of rare complications, you should indicate to your doctor before the procedure that you wish for all possible complications to be fully discussed..
Because of the cancer risk, it is recommended that all polyps found at the time of the colonoscopy be removed. However, it may not be possible to discuss the removal with you at the time of the examination as you will be sedated. Therefore, if you agree to the polyps being removed during the procedure, please sign the consent form. If you have any queries or reservations about this, please inform your doctor.
In the unlikely event of haemorrhage occurring, blood transfusion may be necessary.
The sedative painkiller you are given before the procedure is very effective in reducing the discomfort. However, it may also effect your memory for a short period afterwards. Even when the sedative appears to have worn off, you may find you are unable to recall details of your discussion with the doctor. For this reason a relative or friend should come with you if possible. If you do not recall discussions following the procedure you should contact your doctor. Lastly you should not drive that day.
If you have any severe abdominal pain , bleeding from the back passage, fever or other symptoms that cause you concern, you should contact your doctor immediately.