Preventing Colon Cancer with Endoscopy
In gastroenterology, or the study of the digestive system and all related disorders, colonoscopy is the most important endoscopic procedure designed to screen for colon cancer. Other endoscopy procedures include sigmoidoscopy, which is used to examine the lower third of a patient’s colon or large intestine, and upper endoscopy, which is used to examine a patient’s esophagus and small intestine. These days, there are also less invasive endoscopic procedures available to patients who would prefer not to undergo sedation for a traditional endoscopy. These non-invasive medical imaging techniques include virtual colonoscopy, which combines CT scanning and traditional colonoscopy, and capsule endoscopy, which allows the patient to swallow a camera shaped like a pill (not useful for colon cancer screening.) Please note that these more modern imaging techniques are limited in their ability to detect pre-cancerous growth in the body. For patients at risk for colon cancer, a colonoscopy is almost always the best screening test because it allows the gastroenterologist (GI doctor) to examine the entire length of the colon. During a colonoscopy, surgeons can also perform polyp removals or biopsies to remove abnormalities as they are detected.
During an endoscopy procedure, a doctor will look inside a patient’s body using an endoscope, an instrument designed to examine the inner wall of a hollow organ such as the large intestine or the esophagus. Endoscopes are less like other medical imaging devices because an endoscope is inserted directly into the organ of the patient. Endoscopes can be flexible, allowing for guidance through the GI tract, or they can be quite rigid. Usually, an optical fiber light is attached to the end of any endoscope, so that doctors can see the inside of the body as images for captured and displayed on a television or computer monitor. Sometimes, the device will also include an eyepiece that the doctor can look into to further examine the patient.
An endoscopy performed by a gastroenterologist will involve organs associated with the gastrointestinal tract (GI tract), including:
• esophagus, stomach, duodenum (esophagogastroduodenoscopy or EGD)
• small intestine (enteroscopy)
• large intestine or colon (colonoscopy or sigmoidoscopy)
• bile duct (endoscopic retrograde cholangiopancreatiography or ERCP)
• rectum (rectoscopy) and anus (anoscopy)
Sometimes a cutting device is attached to the end of an endoscope, as in the case of a polyp removal or biopsy, to transform the endoscope into a surgical tool. During this process, a tube-shaped endoscope that also has the ability to pump air or gas into the patient’s colon holds the colorectal walls open while a surgeon cuts away pieces of pre-cancerous or cancerous tissue using the cutting device. Endoscopic surgery is a great alternative to open surgery because it is less invasive and is generally safer, with fewer reported instances of post-procedural complications.
The patient is almost always sedated during an endoscopic surgery, as the endoscope will need to stretch the colon and allow for inner access. Many patients do not remember colonoscopy or other endoscopic procedures because the sedation can make the patient feel woozy or sleepy during the procedure and for several hours after. Also, they might experience soreness in the areas of the body where an endoscope was inserted.
Contact a GI Doctor about Screening for Colon Cancer with Endoscopy
One of our colonoscopy specialists will be happy to inform you about all the endoscopic procedures available to you for colon cancer screening. It is generally recommended that after the age of 50, patients get their colons screened, as the risk of colon cancer dramatically increases with age. If there are no polyps detected, this exam should be repeated at least every 10 years. For those who have precancerous polyps repeat screening examinations should be at least every 5 years, and even sooner if there are greater than 3 polyps or the polyps show high risk features that could become colon cancer earlier than the standard 10 year follow-up.
Reviewed 12/12/2011 by David M. Nolan, M.D.
Diplomate of the American Board of Internal Medicine, 2011
Currently a Fellow of Gastroenterology, at UCI 2011-2014