COLONOSCOPY: A LIFE-SAVING PROCEDURE
Have you had a colonoscopy? If you’re 45 years old or older, and haven’t had one, you need to. In fact, if you know you should have one but have put it off, you’re ignoring a procedure that can save your life. The value of a colonoscopy cannot be understated. It’s such a simple procedure that everyone should have one according to the schedule established by professional organizations who make such guidelines.
Just as the dermatologist diagnoses skin cancer by careful visual inspection of the patient’s skin, the gastroenterologist diagnoses colon cancer by direct visualization of the inner lining of the colon, ie. COLONOSCOPY. To accomplish this, he uses a flexible fiber-optic colonoscope. Technological advances in fiber-optics have improved visual clarity so much that the endoscopist can see the mucosal lining clearly enough to see subtle abnormalities that look suspicious enough to warrant biopsy. When the endoscopist sees suspicious areas in the lining (mucosa), he has the capability to biopsy the area through the colonoscope and submit the specimen for microscopic analysis.
Colonoscopes come in various lengths, but the standard length is 100 centimeters (39.37 inches). Depending on the size of the patient, a longer scope may be used. On the far end of the scope is a small camera used for taking photos of the inner lining and suspicious looking areas. The scope is flexible and has controls that the doctor uses to bend or curl the scope as it is advanced through the colon. This flexibility and maneuverability are needed because the scope has to be threaded from the rectum, up the descending colon on the left side, around a 90° turn called the splenic flexure, across the transverse colon, through the hepatic flexure (another 90° turn), and down the ascending colon on the right side. Sometimes, the endoscopist is even able to pass the scope into the last part of the small intestine called the terminal ileum.
Passing the scope through these twists and turns can be difficult, but in expert hands the procedure can be done 20-30 minutes. After inserting the scope into the rectum, it is slowly advanced forward. The colon collapses around the end of the scope making it difficult to know which way to bend the scope as it advances. When it can’t be determined which way to go, the endoscopist can pump a small amount of air through the scope into the colon to expand it. It’s then very easy to see down the opening and know which direction to proceed. Plus, with the colon expanded, the doctor gets a much better 360° view of the inner lining of the colon.
While the doctor is advancing the scope as far as it can safely go, he is looking at the mucosa for polyps, ulcerations, vascular abnormalities, or any suspicious areas. When he sees a lesion, he records how far he has advanced the scope to locate the lesion later when he withdraws the scope. After he has advanced the scope to its full length, or until he no longer feels it’s safe to do so, he will slowly begin to withdraw the scope. It is then he relocates suspicious areas and performs a biopsy.
The colonoscope has a side channel through which a small wire is threaded. At the far end of the flexible wire are small biopsy forceps, and at the operator’s end is a control device the doctor manipulates to use the biopsy forceps. A different wire has a snare at the business end to biopsy polyps. The biopsy specimen remains in the grasp of the instrument as the wire is withdrawn from the channel in the scope.
During the procedure the doctor has two major concerns. Besides carefully examining the colon for possible cancers, he looks for persistent bleeding from a biopsy site, and makes certain he has not poked a hole in the colon (a perforation) from over stretching it with air or advancing the scope too aggressively. Bleeding and perforation happen very rarely in expert hands, but must be avoided at all costs.
The doctor can easily see bleeding from a biopsy site and stop it by cauterizing the site if necessary. Perforations, however, are a different situation; they may not be detected until afterward when the patient wakens from the anesthesia and complains of severe abdominal pain. Normally, upon awakening, a colonoscopy patient will be groggy and lethargic, but will have no abdominal pain. He may feel bloated and pass a lot of intestinal gas, but he should be pain free. If he does have pain, tests to find the cause are imperative.
Colonoscopy saves lives because it is very effective at finding pre-cancerous and cancerous growths in the colon at an early stage. The lining (mucosa) is directly visualized for suspicious lesions. Colon cancers are either flat (sessile) on the surface of the colon lining or on the tip of a polyp (polypoid). Some lesions when found are obviously cancerous because of their appearance, but others, especially those in the tip of a polyp, are not. They can only be found by microscopic examination after they are removed as a biopsy specimen. Having a colonoscopy finds these lesions in their early stages and removing them can be curative.
When a pre-cancerous or cancerous lesion is found, it alerts the doctor to the need for a repeat colonoscopy at a time sooner than the usual ten years. This time interval is determined by the results of the biopsy. It could be as soon as three months or as long as a year. These recommended time intervals are determined by the American Cancer Society, the American College of Gastroenterology, and my least favorite, the USPSTF (U.S. Preventive Services Task Force). Gastroenterologists are very familiar with these guidelines and follow them explicitly.
Dr. G’s Opinion: I’m convinced, as are most gastroenterologists, that colonoscopy is an essential procedure that saves lives. Every adult over age 45 should have one every ten years. If you don’t, you’re living dangerously and being foolish; especially, if you have a family history of colon cancer. It is a familial disease, ie. if one family member has it, there’s a high likelihood others will, too.
Many people have unwarranted fears of colonoscopy and put it off as a result. It is done under sedation which eliminates pain, and allows the doctor to perform the procedure without resistance. And patients awaken quickly after it’s over. Adverse events are very rare. A good outcome is most often the result. If the exam is negative, that’s good news. If something is found, it is biopsied, staged, treated, and followed up with regular surveillance colonoscopies. In so doing, it effects a “cancer cure.” Intellectually, people know they should have a colonoscopy, but getting them to do it is another thing.
Please get a colonoscopy. It’s definitely worth the time and money. I’ve seen many patients who were discovered to have cancer in the very tip of a small polyp. If they had not had a colonoscopy, that cancerous polyp would have gone undetected and grown into an invasive tumor that later could spread to the liver. When that happens, the game is over. So don’t put it off. It’s not as bad as you think! The peace of mind gained from knowing you have a normal colon will make you thankful you had the procedure.
Reference: https://www.mayoclinic.org/tests-procedures/colonoscopy/about
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