A colonoscopy procedure enables your physician to examine the lining of the colon (large bowel) for abnormalities and inflammation. Colonoscopies are often used to diagnose and to assess the extent and severity of CD and UC.
The endoscope used in a colonoscopy is known as a colonoscope. It is a narrow, flexible tube, long enough to examine the whole of the colon, and, if necessary, the lower end of the small intestine as well. It is inserted through your anus, into your rectum and then on into your colon.
DBE or "enteroscopy" is another way to visualize most or all of the lengthy small bowel. It is a scope that is designed specifically to allow it to be advanced much further than a standard gastroscope or colonoscope. It can be performed through the mouth or through the rectum and by combining both routes, one can possibly visualize all of the small bowel. Not all gastroenterologists perform this procedure – only a few who are trained in this technique perform this.
Colonoscopy is the “gold standard” for detection of IBD, polyps, and cancer. It is the most accurate test and allows biopsy or removal of growths, unlike any other colon test. Colonoscopy is thought to detect more than 80% of polyps and more than 95% of colon cancers. However, the test is not perfect, and there is a small chance that polyps, and even cancer on rare occasions, can be missed.
These ones may also be recommended to check for dysplasia (abnormal cell changes which can be an early sign of bowel cancer) in people with longstanding and extensive CD or UC. Guidelines advise that most people should have a colonoscopy 8 to 10 years after the start of CD or UC. Depending on what is seen, it is likely that follow-on colonoscopies will be recommended every one, 3 or 5 years. People who also have Primary Sclerosing Cholangitis are at an increased risk of colorectal cancer, and therefore surveillance colonoscopy is recommended at diagnosis, then every 1 to 2 years. Chromoendoscopy, which involves spraying special dyes onto the lining of the colon, is used to help to identify abnormal cells.
For colonoscopy to be successful, accurate and complete, the colon has to be completely clean (empty of stool/feces). Your physician will give you detailed instructions regarding the dietary restrictions to be followed and the bowel cleansing routine to be used.
In general, preparation consists of either drinking a large amount of a special cleansing solution or several days of clear liquids, laxatives, and enemas prior to the examination. It is important to follow the written instructions you will be given about taking the preparation, otherwise your test may be unsuccessful and will need to be repeated.
Follow your IBD specialist’s instructions carefully. If you do not, the procedure may have to be canceled and repeated later.
If your doctor thinks an area of the bowel needs to be evaluated in greater detail, a forceps instrument is passed through the colonoscope to obtain a biopsy (a sample of the colon lining). This specimen is sent to the pathology laboratory for tissue analysis. Biopsies are taken for many reasons including identifying the inflammation and do not necessarily mean that cancer is suspected.
If colonoscopy is being performed to identify sites of bleeding, the areas of bleeding may be controlled through the colonoscope by injecting certain medications or by coagulation (sealing off bleeding vessels with heat treatment)
If polyps are found, they are generally removed. None of these additional procedures typically produce pain.
Colonoscopy is generally safe when performed by physicians who have been specially trained and are experienced in these endoscopic procedures. One rare complication (approximately 1 in 500 to 1000) is a perforation or tear through the bowel wall that will usually require surgery. During the surgery, the hole will be closed. Bleeding may occur from the site of biopsy or polypectomy. This bleeding is usually minor and stops on its own or can be controlled through the colonoscope. Rarely, blood transfusions or surgery may be required. Bleeding can occur up to 10 to 14 days after polypectomy, especially if blood thinners, Aspirin, Plavix or anti-inflammatory agents are started after polypectomy.
Other potential risks include a reaction to the sedatives used to make you relaxed and drowsy for the procedure.
Localized irritation of the vein where medications were injected may rarely cause a tender lump lasting for several weeks, but this will go away eventually. Applying warm packs or warm moist towels may help relieve discomfort.
Although complications after colonoscopy are uncommon, it is important for you to recognize early signs of possible complication.
Contact your physician, who performed the colonoscopy, or go to the nearest emergency department if you notice any of the following symptoms:
severe abdominal pain
fever and chills
rectal bleeding of more than one-half cup. Bleeding can occur up to 10-14 days after colonoscopy and/or polypectomy.
Most medications may be continued as usual, but some medications can interfere with the preparation of the examination.
It is, therefore, best to inform your physician of your current medications as well as any allergies to medications several days prior to the examination.
Aspirin products, arthritis medications (NSAID’s or anti-inflammatory agents), anticoagulants (blood thinners), insulin, and iron products are examples of medications whose use should be discussed with your physician prior to the examination.
You should alert your physician if you have required antibiotics prior to undergoing past dental procedures, since you may need antibiotics prior to colonoscopy as well.
If you are diabetic, you must speak with your family physician (or the physician who prescribed your diabetes medication) about using insulin or pills for your diabetes on the day of your procedure.
The Registration Clerk will register you for the procedure. Please have your photo identification and Alberta Personal Health Card with you.
The Endoscopy nurse will get you ready for the procedure. Paperwork for the procedure will be reviewed and you will be asked to sign the procedure consent. You will change into a gown and lie on a stretcher. you may be offered sedation for the colonoscopy to help you feel sleepy and relaxed. Children are usually given a general anesthetic. The nurse will start an intravenous (IV) in your arm. When it is time for your colonoscopy, you will be taken to the procedure room on a stretcher.
Colonoscopy is usually well tolerated and rarely causes much pain. There is often a feeling of pressure, bloating, or cramping at times during the procedure.
The procedure usually takes 15 to 30 minutes. The team of people in the procedure room will be doctors and nurses.
You will lie on a stretcher on your side or on your back. Your oxygen level, heart rate, and blood pressure are monitored during the procedure.
The physician will slowly advance the colonoscope into the anus and through the large intestine while examining the bowel lining. In some cases, the passage of the colonoscope through the entire colon to its junction with the small intestine cannot be achieved. The physician will decide if the limited examination is sufficient or if other examinations are necessary. As the colonoscope is slowly withdrawn, the lining is again carefully examined.
You will be taken by stretcher from the procedure room to the recovery room. Your oxygen level, blood pressure, heart rate, and breathing will be monitored by recovery nurses after the procedure.
You may have some cramping or bloating because of the air introduced into the colon during the procedure. This should disappear quickly with the passage of flatus (gas). The nurse will check with you if you have passed gas.
You will stay in the recovery room until the nurse determines that you are ready to go home.
Your physician will provide you with a preliminary report of the procedure in a letter or will explain the procedure to you.
If you have been given medications during the procedure, a responsible adult must accompany you home from the procedure because of the sedation used during the procedure. If you are unable to get a responsible adult to accompany you home, the procedure may either be canceled, rescheduled or it may have to be done without sedation. Even if you feel alert after the procedure, your judgement and reflexes may be impaired by the sedation for the rest of the day, making it unsafe for you to drive or operate any machinery.
While at home, you may have some cramping or bloating but this should disappear with the passage of flatus (gas). Persistent pain is very uncommon after colonoscopy. You should contact your physician who performed the colonoscopy or go to the nearest emergency department if this happens.
Generally, you should be able to eat after leaving the endoscopy, but your doctor may restrict your diet and activities.