A colonoscopy consists of introducing a long flexible tube into the rectum. The tip of the tube, which is no larger than a finger, is equipped with a camera that provides images of the inside of the rectum and large intestine, enabling the doctor to detect any abnormalities. A colonoscopy generally takes a few minutes to complete.
A colonoscopy allows the doctor to look inside the large intestine and can be recommended for a variety of reasons. It allows the physician to take samples of intestinal tissue, remove polyps, or stop intestinal bleeding. Colonoscopy is used to diagnose and monitor inflammatory bowel diseases and to determine the cause of persistent bleeding. The physician can also use this test to identify any suspicious growths before they develop into cancer.
The Canadian Cancer Society recommends that men and women over the age of 50 have a fecal occult blood test at least every 2 years. In the event where the fecal blood test is positive, a colonoscopy or barium enema is the next step. Those with a higher risk of developing colorectal cancer should also have a colonoscopy. Higher risk persons include those with a first degree relative (brother, father, etc.) who has had this type of cancer, those with a personal history of colorectal cancer, anyone with inflammatory bowel disease or familial adenomatous polyposis and those who have polyps in the colon or rectum.
The colon generally holds feces. To get a clear view of the colon, it is crucial that it be emptied and cleansed. Various laxative preparations are commonly used to that end. Each health care facility has its own protocol. Before going for a colonoscopy, make sure that you have read all the instructions that were given to you on how to prepare and make sure that you have all the medication needed to prepare for the procedure. Here is a short list of some of the products that are used before a colonoscopy.
|Bisacodyl (Dulcolax®)||Tablet and/or suppository||Depending on the protocol, 1 to 3 tablets or 1 to 2 suppositories, the night before the colonoscopy.|
|Electrolyte with polyethylene glycol (Peglyte®)||Liquid solution||Drink 4 litres of solution the night before the examination.|
|Liquid solution||Drink the entire bottle (240 mL) the night before the examination.|
|Powder||Drink 2 sachets diluted in 150 mL of water each, at a few hours interval, the night before the examination.|
|Sodium phosphate (Fleet ®)||Rectal enema||An enema is often recommended the night before and the morning of the colonoscopy.|
|Sodium phosphate (Fleet phosphosoda)||Liquid solution||Drink 2 bottles, at a few hours interval, the night before the examination.|
Colonoscopies are performed at the hospital. Once there, you will be asked to remove any jewellery and to change into a hospital gown to facilitate the examination. Most of the time, a sedative is given to help the patient relax while remaining conscious. The medication makes the procedure more bearable.
Patients are asked to lie on their left side, with their knees folded. The device is then inserted into the rectum and the examination begins. You will feel the need to defecate while the camera is in the large intestine. Air is occasionally introduced into the colon to allow for a better view of the intestinal walls. A colonoscopy generally takes 20 to 45 minutes to complete. After the procedure, it is normal to experience some cramping.
During the procedure, the physician may comment on what he is seeing. If an abnormal lesion is detected, a small sample will be taken and sent for further testing. The physician may also see benign or precancerous polyps which he may or may not choose to remove. The colonoscopy is used to detect early stage cancer as well as any inflammation or infection in the colon. All findings are subjected to additional testing to provide an accurate picture of the situation.
Although very rare, complications can occur. If you experience persistent bleeding, significant pain, nausea or vomiting after the procedure, immediately contact the centre where you had your colonoscopy.
What to know before going for this test
Before going for a blood test, examination or other, it is always a good idea for you to have a complete list of all prescription or over the counter medications and/or natural products you may be taking. Unless otherwise indicated, it is recommended that you continue to take your medication as usual when going for blood tests. If you are unsure or have any questions, your pharmacist will be able provide you with additional information.
© Copyright Vigilance Santé
The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.