A colonoscope is a long flexible tube that is about the thickness of a finger. It is inserted through the rectum into the large intestine (colon) and allows the physician to carefully examine the lining of the colon. Abnormalities suspected by X-ray can be confirmed (or refuted) and studied in detail. Abnormalities which are too small to be seen on X-ray may also be identified. If the doctor sees a suspicious area or needs to evaluate an area of inflammation in greater detail, he can pass an instrument through the colonoscope and take a small piece of tissue (a biopsy) for examination in the laboratory by a pathologist. Biopsies are taken for many reasons and do not necessarily mean that cancer is suspected.
During the course of the examination, a polyp or abnormal growth of tissue varying in size from a tiny dot to several inches may be found. If your doctor feels that removal of the polyp is indicated, he will pass a wire loop (or snare) through the colonoscope and sever the attachment of the polyp from the intestinal wall by means of an electrical current. If additional polyps are detected, they may be removed as well. There are other methods of removing polyps. Most often, this involves using a biopsy forceps to remove the polyp either with or without applying electrical current. Any time electrical current is used, the endoscopy nurse will attach a cold sticky "grounding pad" to your hip or thigh. You should feel no pain during removal of the polyp. Although the majority of polyps are noncancerous (benign), a small percentage may contain an area of cancer in them or may develop into cancer. Removal of colon polyps, therefore, is an important means of prevention and cure of colon cancer, which is a leading form of cancer in the United States.
For the best possible examination, the colon must be completely empty of waste material. This is best accomplished by drinking a specially designed nonabsorbable solution which purges the intestine the evening before the procedure as described in Preparing for your Colonoscopy. For most patients, we use a preparation using a liquid called phosphosoda but we may use a preparation using GoLytely instead. Your doctor will give you detailed instructions in the cleansing routine he feels is best for you as some patients may have a specific indication for one preparation solution or the other. Be sure to let your doctor know if you are allergic to any drugs. Aspirin and arthritis medications should be discontinued one week prior to the examination, although Tylenol or similar acetaminophen medications are allowed. A companion must accompany you to the colonoscopy because you will be given medication to help you relax. It will make you drowsy so you will need someone to take you home. You will not be allowed to drive following the procedure. Even though you may not feel tired, your judgment and reflexes may not be normal.
The nurse will attach EKG leads to your chest, place a blood pressure cuff around your arm, place a small probe on your finger to monitor the oxygen level in your blood and start an intravenous line. Your doctor will give you medication through the vein to make you relaxed and sleepy. While you are lying in a comfortable position on your left side, a rectal examination is performed, mainly to lubricate the anal canal. The colonoscope is inserted into the rectum and gradually advanced through the colon while the lining is examined thoroughly. The colonoscope is then slowly withdrawn while the intestine is again examined carefully. Many patients fall asleep during the examination. There may be some discomfort during colonoscopy particularly while the scope is being advanced through the colon. This is usually mild but may be more significant. In rare cases, passage of the colonoscope through the entire colon cannot be achieved. A limited examination may be sufficient if the area of suspected abnormality was well visualized. After the procedure, you will be kept in the endoscopy area until most of the effects of the medication have worn off. You may feel bloated for a few minutes afterwards. You will be able to resume your diet after the procedure unless otherwise instructed.
Colonoscopy and polypectomy are safe, accurate, and are associated with very low risk when performed by physicians who have been specially trained and are experienced in these procedures. Even in experienced hands, however, lesions such as polyps and cancers might not be visualized and complications may occur.
One possible complication is perforation in which a tear through the wall of the bowel may allow leakage of intestinal fluids. This complication may require surgery but may also be managed with antibiotics and intravenous fluids in selected cases, particularly if recognized early. Pain in the abdomen following the examination might indicate a perforation. Contact the office if this occurs.
Bleeding may occur from the site of biopsy or polyp removal. It is usually minor and stops on its own or can be controlled by cauterization (application of electrical current) through the colonoscope. Bleeding may be delayed up to two weeks following polyp removal. Aspirin and non steroidal anti-inflammatory medications may prolong bleeding. Rarely, transfusions or surgery may be necessary. If you experience bleeding after the procedure, contact the office.
Localized irritation of the vein may occur at the site of medication injection. A tender lump develops which may remain for several weeks to months but goes away eventually.
Other risks include drug reactions and complications from unrelated diseases such as heart attack or stroke. Death is extremely rare, but remains a remote possibility.
If a complication or a question of one develops contact the office immediately.