During this examination we look for any abnormalities, redness, irritation, or polyps, and appropriate measures are taken to determine why the irritation exists, or in fact to remove the polyps. The advantage of colonoscopy over barium enema, virtual colonoscopy, and other methods of viewing the colon, is that at the time of the examination, the colon is both examined, biopsies may be taken if necessary, and the removal of polyps, or small groups within the colon, can be performed.
It is often suggested that everybody over the age of 50 have a colonoscopy. If it's normal, it should be repeated every 5 to 10 years thereafter. People are very concerned that every five to 10 years may not be frequent enough to look for colon cancer. Colon cancer grows very slowly, and it takes somewhere between 3 and 8 years for colon cancer to develop. Therefore, doing a colonoscopy every five years, assuming the previous examination has been normal, is quite reasonable. There certainly are some circumstances when we do it more frequently, but that's less commonly the case. If, during an examination, one has a polyp that is large and has the potential to become cancerous (this is detected by examination under the microscope), then a follow-up colonoscopy is done 3 and not 5 years later.
Typically, a colonoscopy takes between 10 and 15 minutes. Most patients choose to get sedation for the examination so that they're sleepy if not asleep, but there certainly are some patients who prefer no sedation. The advantage of getting sedation is that one is comfortable, and certainly the anxiety is less. If sedation is given, that person is generally instructed not to drive for 24 hours, and should go home and rest for the remainder of the day. If no sedation is given, the individual can go back to work or his or her normal activities immediately. Usually people feel somewhat bloated after a colonoscopy but this passes very quickly, and the aftereffects, several hours later, should be minimal.
Most people say that the colonoscopy itself is less uncomfortable than the preparation. There are several different preparations on the market, and the preparation should be tailored to the individual patient. The preparations range from drinking a gallon of prescription liquid over the course of two or 2 1/2 hours, to taking several laxatives, to taking 40 pills, which are essentially laxatives. It's absolutely critical that the entire preparation as directed be followed, or else we are frequently unable to either complete the colonoscopy, or to examine the wall of the bowel very carefully. Occasionally, in fact, we have to reschedule the examination entirely. We always make a point of stressing how critical the preparation is, because we find that the most common problem is an inadequate preparation. We encourage all patients to review the instructions as soon as they get them, and then again several days before the examination. This is important both to become familiar with the instructions for the evening before the examination, as well as the fact that the diet, the day before the examination is very frequently quite restricted.
The morning of the examination, the patient comes to the facility, typically a friend or family member is available to drive them home. The duration of stay, including the examination, the preparation just before the examination including the nurses taking the patient's history, and the recovery, is between 1 and 2 hours. We ask patients to plan their days accordingly.
We make every attempt to contact the patient with laboratory results as soon as they become available. Generally this takes 4 to 5 days. At that time we tell them when they need to have a colonoscopy performed again.
Many patients ask how we remove polyps. We remove polyps at the time of the examination, and we do not have to insert a separate instrument to do so. We put a looped wire around the polyp, apply electrical current, cauterize and burn off the polyp. We then grab the polyp and send it off to the laboratory. Interestingly, the colon has no nerve cells in the inner walls, some patients can feel this, and there is no discomfort whatsoever. Because we use electrical current to remove the polyp, there should be no bleeding.
It's our very firm belief and hope that by utilizing colonoscopy on a periodic basis, we have a window of opportunity. We can remove precancerous lesions when they are small, and can be removed with the colonoscope, instead of surgically. While we certainly can't stop all cancers from developing, we think that we can have enormous impact on the incidence of colon cancer