< to procedures A Conversation on Colon Screening and Colonoscopy by Dr. Marc Marcum 1. What are the indications for colonoscopy? There are a number of reasons to consider having a colonoscopy. The most prominent would be symptoms relating to the colon such as a change in bowel habits, like constipation or frequent diarrhea or a sensation that a bowel movement should pass but won’t. Also, a change in the caliber of a stool can signal a problem with the colon. Most commonly however, patients present with bleeding which can range from bright red blood associated with the bowel movement or on the paper following a stool, or it can also be manifested as black tarry bowel movements. Recently there has been an increased interest in preventive medicine to try and prevent the occurrence of problems, in this instance colon cancer. Certainly patients with a family history of colon cancer or polyps or a family history of inflammatory bowel disease should be considered for evaluation with a colon exam. We have also tried to identify an at risk population or the age at which incidence of colon polyps and cancer begins to increase. This seems to be at about age 50 for patients without a family history and at an earlier age for patients with a family history of colon cancer. Again, depending somewhat on their history. 2. What procedures are available for colon screening? There are number of procedures available for colon screening some of which you may have already experienced. The first being a digital rectal examination which your doctor may have already performed. This may be coupled with an examination called a hemoccult examination to attempt to identify occult blood in the bowel movement. Additional tests which could be performed include a flexible sigmoidoscopy which by itself is not an adequate screening examination because it only looks at the last foot or so of the colon. This is usually coupled with an examination called a barium enema which is an x-ray procedure in which a catheter is placed in the rectum and the colon is filled with dye and x-rays are obtained. Neither of these alone is an adequate screening examination, and the two of these together can be utilized for colon screening. They do however, have about a 15% failure rate in identifying lesions if they are present, and if a lesion is seen on the barium enema it may necessitate a second procedure. The best screening examination in my estimation is a colonoscopy. It has the ability to see the entire colon and results in a completion rate with the entire colon being visualized in about 98% of patient. It also affords the opportunity to take picture or biopsy lesions which are seen or potentially even remove these. It has a lower failure rate of about 5% meaning that only 5% of lesions which are present would be missed on colonoscopy. 3. The risks and complications associated with the procedure. As with any invasive procedure there are risks and complications associated with colon cancer screening or colonoscopy. There is the potential for over sedation because during the procedure we do administer both pain medication and anxiety medications and also medication to help the colon relax. This is very unlikely and these can be rapidly reversed with counter-acting agents. There is the potential that we would not be able to complete the examination either because of findings at the exam or because of anatomy or adhesions from previous surgery. Another potential complication is bleeding. This certainly can occur if a large polyp is removed, particularly if a patient has been on anticoagulant therapy or aspirin. The last complication which we worry about the most, but fortunately is very uncommon occurring in only about 1 out of 500 examinations, is the potential for perforation. This is more likely to occur if the patient has extensive diverticular disease or has a large polyp which has to be removed, but can occur in anyone undergoing this procedure and in the lesser procedures of sigmoidoscopy or a barium enema. Again, the risk is very unlikely. If it does occur, it would usually require surgery to repair. 4. Preparation Preparation for the examination is really the most unpleasant portion. It entails generally drinking a large volume bowel prep. We generally use GoLYTELY for our prep, and we have found that it makes it more palatable often times to mix this with some Crystal Light drink mix and cool it slightly. We recommend that you usually start at about 2 o’clock in the afternoon and try and complete the prep over about 4 hours. We usually utilize an 8 oz glass drinking an 8 oz glass of fluid every 15 min. If you develop nausea and vomiting while performing the prep, we recommend that you slow down on drinking it to a more relaxed pace and also try and lie with your right side down to try and facilitate emptying of the stomach. If after trying these measures, you are still unable to tolerate the GoLYTELY prep, we generally recommend that you take one bottle of Magnesium Citrate which is available over the counter by mouth, and two fleets enemas and hopefully this will be enough to cleanse the colon adequately for your examination. Generally, the colon is adequately cleansed when you are only passing some yellow or brown watery type secretions. 5. What can you expect on the day of the procedure? We ask that you not have anything to eat or drink after midnight on the day prior to your procedure. You will need someone with you to drive you home following the examination because of the sedation you receive during the procedure. We ask you to arrive two hours before the scheduled time of your procedure because it often times occurs that as we do several of these examinations sequentially that your examination time may be moved up. It also allows plenty of time for the registration process and also for the nurses to begin your IV which we will use to administer your sedation. You will then be brought to the Endoscopy Suite. At that time, you will see your doctor. We will begin you on some sedation in your vein in order to help you relax and also to help your colon to relax. The procedure itself takes about 20 to 30 min unless we encounter polyps or pathology that would require additional time for removal. During the procedure, you are generally sedated to the point where you won’t recall any of the examination and usually the first thing that patients remember is when they are transported to the Recovery Room. At this point, you will be joined by your family member and will generally stay here about 30 to 45 min as you awaken from the sedation. We also ask that you again don’t plan to return to work that day because the medications that we give you for the examination can affect your judgment or the ability to perform your job safely. If after reviewing this you have further questions, please give our office a call at 897-5139. Questions? Other Frequently Asked Questions