The term "colonoscopy" means looking inside the large intestine ( colon). It is a procedure performed by a gastroenterologist.
The colon, or large bowel, is the last portion of your digestive or GI tract. It starts at the cecum, which attaches to the end of the small intestine, and it ends at the rectum and anus. The colon is a hollow tube, about five feet long, and its main function is to store unabsorbed food products prior to their elimination.
The instrument that is used to look inside the colon is called colonoscope, which is a long, thin, flexible tube with a tiny video camera and a light on the end. By adjusting the various controls on the colonoscope, the doctor can carefully guide the instrument in any direction to look at the inside of the colon. The picture from the colonoscope is shown on a TV monitor, and gives a clear, detailed view.
Colonoscopy is more precise than barium enema which is merely an Xray of the colon after enema using barium and is rarely done now a days Colonoscope also allows other instruments to be passed through . These may be used, for example, to painlessly remove a suspicious-looking growth or to take a biopsy-a small piece 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, an instrument used to screen the lower part of the large bowel only. The colonoscope, however, is long enough to inspect all of the large bowel and even part of the small intestine. Colonoscopy is a safe and effective way to evaluate problems such as blood loss, pain, and changes in bowel habits such as chronic diarrhea . Colonoscopy can also identify and treat active bleeding from the bowel.
Colonoscopy is also an important way to check for colon cancer and to treat colon polyps - abnormal growths on the inside lining of the intestine. Polyps vary in size and shape and, while most 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.
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 difficult part of the entire exam. It is essential that you complete this step carefully, because how well the bowel is emptied determines the success of the procedure.
Various methods can be used to help cleanse the bowel. Often, a liquid preparation or powder to be dissolved in water, designed to stimulate bowel movements is given by mouth, which may cause bloating. Other laxative preparations, such as castor oil, may also be used. Whatever method or combination of methods that is recommended for you, be sure to follow instructions as directed.And remember, you should not consume anything within four hours before your colonoscopy. Colonoscopy can be done in either a hospital or outpatient office. You’ll be asked to sign a form that gives your consent to the procedure and states that you understand what is involved. If there is anything you don’t understand, ask for more information.
Most medications may be continued as usual, but some medications can interfere with the preparation or the examination. It is therefore best to inform your physician of your current medications as well as any allergies to medications several days prior to the examination. Aspirin products, arthritis medications, anticoagulants (blood thinners), insulin, and iron products are examples of medications whose use should be discussed with your physician prior to the examination. You should alert your doctor if you require antibiotics prior to undergoing dental procedures, since you may need antibiotics prior to colonoscopy as well.
During the procedure, the doctor will try to avoid discomfort. An intravenous, or IV, line will be inserted to give you medication to make you relaxed and drowsy. The drug will enable you to be drowsy but it also prevent you from remembering much of the experience.
Once you are fully relaxed and sleepy, your doctor will do a rectal exam with a gloved, lubricated finger; then the lubricated colonoscope will be gently inserted. As the scope is slowly and carefully passed, you may feel as if you need to move your bowels, and because air is introduced to help advance the scope, you may feel some cramping or fullness. Generally, however, there is little or no discomfort. In some cases, passage of the colonoscope through the entire colon to its junction with the small intestine cannot be achieved due to anatomical variations due to poor cleansing or if the oxygen saturation drops to critical levels during the procedure.
Polyps are abnormal growths from the lining of the colon which vary in size from a tiny dot to several inches. They are usually genetic in origin. The majority of polyps are benign (noncancerous) but the doctor cannot always tell a benign from a malignant (cancerous) polyp by it outer appearance alone. For the reason, removed polyps are sent for tissue analysis. Removal of colon polyps is an important means of preventing colorectal cancer. Tiny polyps may be totally destroyed by biopsy, cold snaring, fulguration (burning), but larger polyps are removed by a technique called snare polypectomy. The doctor passes a wire loop (snare) through the colonoscope and severs the attachment of the polyp from the intestinal wall by means of an electrical current. You should feel no pain during the polypectomy.
Colonoscopy and polypectomy are generally safe when performed by physicians who have been specially trained and are experienced in these endoscopic procedures. Although colonoscopy is a safe procedure, complications can sometimes occur. These include perforation - a puncture of the colon walls, which could require surgical repair. Biopsy or polypectomy can be associated with bleeding. It is usually minor and stops on its own or can be controlled through the colonosocope.
Rarely 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.
The time needed for colonoscopy will vary, but on the average, the procedure takes about 20 to 30 minutes rarely in difficult cases 40 to 60mts.
Afterwards, you’ll be cared for in a recovery area until the effects of the medication have worn off. You may have some cramping or bloating because of the air introduced into the colon during the examination. This should disappear quickly with passage of flatus (gas). Generally, you should be able to eat after leaving the endoscopy, but your doctor may restrict your diet and activities, especially after polypectomy.
At this time, your doctor will inform you about the results of your colonoscopy and provide any additional information that you need to know. You’ll also be given instructions about how soon you can eat and drink, plus other guidelines for resuming your normal routine. There is a possibility that you may forget the discussion with your doctor due to the medication. In that case make a follow up appointment with your doctor to discuss the results. . Even if you feel alert after the procedure, your judgment and reflexes may be impaired by the sedation for the rest of the day, making it unsafe for you to drive or operate any machinery.
Average-risk individuals should be offered screening beginning at age 50 years ( ASGE recommendation) If you have a first degree relative with colon cancer the screening starts at 40 yrs.
Surveillance colonoscopy be performed at 1 year after surgical resection of colon cancer. If results are normal, the next colonoscopy should be in 3 years.