The following explains what patients can expect when undergoing a colonoscopy at UW Health in Madison, Wisconsin.
During a colonoscopy a flexible tube with a small lens and video camera is passed the length of the colon. The camera allows the doctor to see the entire colon. The colonoscope also allows tools such as forceps or snares to be passed into the colon to sample tissue or remove polyps.
Colonoscopy is the test most often used to screen for colorectal cancer and polyps. Polyps are growths in the colon that often have pre-cancerous changes. They are known as adenomas. It is not possible to tell by looking at a polyp if it is cancerous or may become cancerous. This is why colonoscopy is used to remove polyps. The technique is called polypectomy. Removal of polyps at colonoscopy is the reason for colorectal cancer screening. It prevents polyps from developing into cancer.
Preparing for Colonoscopy
You will receive written instructions for your colonoscopy in the mail. Generally, the day before your colonoscopy you can have a light breakfast and then clear liquids after noon. In the evening you will begin your bowel prep to clear the colon so the doctor can see inside. The bowel prep is a liquid you drink that causes bowel movements. It is either taken all the night before or more often split between the night before and the early morning of your test. Except for the bowel prep, you should not eat or drink anything after midnight the day of the procedure.
The day of the colonoscopy, most patients choose to have sedation for comfort. With sedation during the test, most patients feel drowsy and do not remember the test being done. As the test is done you may feel bloated or gassy, but generally there is little to no discomfort. It takes 30 minutes or less.
During the test while you are lying on your left side the doctor passes the colonoscope the length of the colon and then views the colon lining as the scope is withdrawn. The doctor will be looking for colon polyps and will remove any found. Polyps are removed with a forceps or snare, sometimes using electrical current. There is no pain or discomfort when polyps are removed.
After the Colonoscopy
If you had sedation, you will rest for about 60-90 minutes. The doctor who did the exam will explain the results to you and discuss future screening. If you had sedation for the exam, you should not drive the rest of the day. You should take the rest of the day off from work. Thirty to fifty percent of the patients will have colon polyps found and removed during the colonoscopy. If you have a polyp removed, you will receive pathology results and recommendations from the doctor within 1-2 weeks of the exam.
|In this powerpoint, Dr. Patrick Pfau explains the
optical colonoscopy procedure.