Colonoscopy is a procedure that enables your physician to examine the lining of the colon (large bowel) for abnormalities by inserting a flexible tube that is about the thickness of your finger into the anus and advancing it slowly into the rectum and colon.
What To Expect
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. Your doctor may give you medication through a vein to help you relax and better tolerate any discomfort from the procedure. You will be lying on your side or on your back while the colonoscope is advanced slowly through the large intestine. As the colonoscope is slowly withdrawn, the lining is again carefully examined. The procedure usually takes 8 – 20 minutes. 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.
The colon must be completely clean for the procedure to be accurate and complete. Your physician will give you detailed instructions regarding the dietary restrictions to be followed, and the cleansing routine to be used. Follow your doctor’s instructions carefully. If you do not, the procedure may have to be canceled and repeated later.
Most medications may be continued as usual. You should inform your physician of all current medications, as well as any allergies to medications, several days prior to examination. However, drugs such as aspirin or anticoagulants (blood thinners) are examples of medications whose use should be discussed with your physician.
Tiny polyps may be totally destroyed by fulguration (burning) or removed using biopsy forceps, but larger polyps are removed by a technique called snare polypectomy. The doctor passes a wire loop (snare) through the colonoscope and severs the attachment of the polyp from the intestinal wall by means of an electrical current. You should not feel pain during the polypectomy. There is a small risk that removing a polyp will cause bleeding or result in a burn to the wall of the colon, which could require emergency surgery.
After the colonoscopy, your physician will explain the results to you. You may have some cramping or bloating because of the air introduced into the colon during the examination. This should disappear quickly with the passage of flatus (gas). Generally, you should be able to eat after leaving the colonoscopy, but your doctor may restrict your diet and activities, especially after a polypectomy.
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 colon lining). This specimen is submitted to the pathology laboratory for analysis. If the 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. Remember, the biopsies are taken for many reasons and do not necessarily mean that cancer is suspected.