What is a Colonoscopy?
A colonoscopy is a minimally invasive examination of the colon. It is a procedure used most often to screen for colon cancer and/or to identify and correct bleeding problems within the colon.
Colonoscopy is an important way to check for colon cancer and to treat polyps. Polyps are abnormal growths on the inside lining of the colon. They vary in size and shape and usually cause no symptoms. It isn’t possible to tell just by looking at a polyp if it is malignant (cancer) or potentially malignant. Since most all cancers of the colon start out as benign polyps years before cancer develops, looking for and removing polyps—that is the chief use of colonoscopy, best do colon cancer prevention. We use colonoscopy to find out reasons for symptoms such as bleeding, persistent diarrhea, and sometimes for abdominal pain or changes in bowel habits. We take photos of what we see; can take out tissue biopsies; remove polyps; and do other treatments. Since the average colon is 4 to 5 feet long and we want to see all of it during the exam, intravenous (iv) sedation is used to keep you very drowsy and comfortable during the procedure. The colonoscopy is a long thin flexible tube using video camera technology and tiny channels in the tube so we can flush water, put air in and remove air, and pass delicate instruments. We view the procedure on a large video monitor. Colonoscopy is usually an outpatient procedure at an endoscopy center.
Uses of Colonoscopy
A Colonoscopy is an important way to check for colon cancer and to treat colon polyps. Polyps are abnormal growths on the inside lining of the intestine; they vary in size and shape and while most polyps are not cancerous, some may turn into cancer. However, it is not possible to tell just by looking at a polyp if it is malignant or potentially malignant. This is why colonoscopy is often used to remove polyps, a technique called a polypectomy. Colonoscopy is also a safe and effective way to evaluate problems such as: Blood loss. Abdominal or rectal pain. Changes in bowel habits, such as chronic diarrhea. Abnormalities that may have first been detected by other studies, such as an inflamed colon noted on a CT scan of the abdomen. Active bleeding from the large bowel. Another advantage of the procedure is that, when needed, other instruments can be passed through the colonoscope. These may be used, for example, to painlessly remove a suspicious-looking growth or to biopsy, that is, take a small piece of tissue for further analysis. In this way, colonoscopy may help to avoid surgery or to better define what type of surgery may need to be done. A shorter version of the colonoscope is called a sigmoidoscope. This instrument is used to screen for problems in the lower part of the large bowel (colon) only. The colonoscope, however, is long enough to inspect all of the large bowel and even the lower part of the small intestine.
How do I prepare for my colonoscopy?
You will be given instructions in advance that will outline what you should and should not do in preparation for colonoscopy; be sure to read and follow these instructions. One very critical step is to thoroughly clean out the colon, which, for many patients, can be the most trying part of the entire exam. It is essential that you complete this step carefully, because how well the bowel is emptied will help determine how well your doctor can examine it during colonoscopy. Various methods can be used to help cleanse the bowel, and your doctor will recommend what he or she prefers in your specific case. Often, a liquid preparation designed to stimulate bowel movements is given by mouth. Additional approaches include special diets, such as clear fluids, or the use of enemas or suppositories. Whichever method or combination of methods is recommended for you, be sure to follow instructions as directed.
After your Colonoscopy
Plan to rest for the remainder of the day after your colonoscopy. This means not driving, so you will need to arrange to have a family member or friend take you home. Occasionally, minor problems may persist, such as bloating, gas or mild cramping, which should disappear in 24 hours or less. A day or so after you are home, you might speak with a member of the colonoscopy team for follow-up, or you may have questions you want to ask the doctor directly
What are the risks of a colonoscopy procedure?
Although colonoscopy is a safe procedure, complications can occur, including perforation or puncture of the colon walls, which could require surgical repair. Complications during a colonoscopy are rare. You should also be aware that colonoscopy is not perfect and even with a skilled physician; some colon lesions (abnormalities) might be missed. When polyp removal or biopsy is performed, hemorrhage — heavy bleeding — may result and sometimes require blood transfusion or reinsertion of the colonoscope to control the bleeding. Be sure to discuss any specific concerns you may have about the procedure with your doctor.
What are my alternatives to this procedure?
Although a colonoscopy is the most accurate form of testing for colon cancer, many seek other forms of screening. First, a virtual colonoscopy uses a scope in the rectum; this test employs a CT scan to view your colon. Another, the cologuard that is a test that requires no prep and can be done in the privacy of your home. You simply take a sample of a bowel movement and mail it to a lab for analysis. The lab looks for both blood and cancer-related DNA in the stool. The last alternative is a sigmoidoscopy. This exam inserts a thin, flexible tube with a tiny camera into the rectum. It’s best for those at low risk for colon cancer, meaning no family history and no previous polyps.