What is a colonoscopy and what preparation is required?
Colonoscopy enables the examination of the lining of your colon (large intestine) for abnormalities. This is performed by inserting a flexible tube. You will be informed of what dietary restrictions to follow and what cleansing routine to use. The colon must be completely clean for the procedure to be accurate and complete, so be sure to follow the instructions carefully.
Can I take my current medications?
Most medications can be continued as usual, but some medications can interfere with the preparation or the examination. Inform your doctor about medications you’re taking, particularly aspirin, arthritis medications, anticoagulants (blood thinners), insulin or iron products. Diabetic medications will need to be adjusted.
If you are taking Warfarin, Plavix, Iscover, Asasantin, Pradaxa, or Xarelto, you must NOT stop these unless instructed by your doctor and alternate arrangements have been made. If you have a coronary stent or a blood clotting disorder, it may NOT be possible to stop these medications.
What happens during colonoscopy?
Colonoscopy is well-tolerated and rarely causes much pain. You might feel pressure, bloating or cramping during the procedure. After receiving sedation, the colonoscope is slowly advanced through your large intestine to examine the lining. The procedure itself usually takes 15 to 30 minutes, although you should plan on two to three hours for waiting, preparation and recovery. In rare cases, the colonoscope cannot be passed through the entire colon to where it meets the small intestine. Although another examination might be needed, you will be informed if a limited examination is sufficient.
What if the colonoscopy shows something abnormal?
If an area needs further evaluation, an instrument is passed through the colonoscope to obtain a biopsy (a sample of the colon lining) to be analysed. Biopsies are used to identify many conditions, and this might even be ordered if the bowel looks normal during the examination. If colonoscopy is being performed to identify sites of bleeding, it may be controlled through the colonoscope by injecting medications or by coagulation (sealing off bleeding vessels with heat treatment). If polyps are found during colonoscopy, these will most likely be removed them during the examination (unless there is a valid reason not to do so). These procedures don’t usually cause any pain.
What are polyps and why are they removed?
Polyps are abnormal growths in the colon lining that are usually benign (noncancerous). They vary in size from a tiny dot to several centimetres. Because cancer begins in polyps, removing them is an important means of preventing colorectal cancer. Polyps are removed with wire loops called snares. That technique involves passing a wire loop through the colonoscope and removing the polyp from the intestinal wall using an electrical current. You should feel no pain during the polypectomy.
What happens after a colonoscopy?
The results of the examination will be explained to you once you are alert, although you’ll probably have to wait for the results of any biopsies performed (this may be done by your GP). Someone must drive you home and stay with you. Even if you feel alert after the procedure, your judgment and reflexes could be impaired for the rest of the day. You might have some cramping or bloating because of the air introduced into the colon during the examination. This should disappear quickly when you pass gas. You should be able to eat after the examination.
What are the possible complications of colonoscopy?
Colonoscopy and polypectomy are generally safe when performed by doctors who have been specially trained and are experienced in these procedures. One possible complication is a perforation, or tear, through the bowel wall that could require surgery. The risk is less than 1 in 1,000. Bleeding might occur at the site of biopsy or polypectomy, but it’s usually minor. The risk is less than 1 in 500. Bleeding can stop on its own or be controlled through the colonoscope; it rarely requires follow-up treatment. Some patients might have a reaction to the sedatives or complications from heart or lung disease.
Although complications after colonoscopy are uncommon, it’s important to recognise early signs of possible complications. Contact your doctor if you notice severe abdominal pain, fever and chills, or rectal bleeding of more than one-half cup. Note that bleeding can occur several days after the procedure.
Please note that whilst colonoscopy is currently the most effective test for screening for bowel cancer, it is not 100% accurate in every case. A thorough bowel preparation resulting in a “clear return” is most important for accurate colonoscopy. Please ask your doctor about anything you don’t understand.
Click here to download and print a copy of the Patient Information for Colonoscopy.