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 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. Biopsies are taken for many reasons and do not necessarily mean that cancer is suspected. A small brush can be introduced as well to collect cells from an abnormal area for examination in the laboratory (a form of pap test or "cytology".)



What is polypectomy?

During the course of the examination, a polyp may be found. Polyps are abnormal growths of tissue which vary in size from a tiny dot to several inches. 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. You should feel no pain during removal of the polyp. Polyps are usually removed because they can cause rectal bleeding or contain cancer. Although the majority of polyps are benign (noncancerous), 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.



What should you expect during the procedure?

Your doctor will give you medication through a vein to make you relaxed and sleepy. While you are lying in a comfortable position, 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 The colonoscope is then slowly withdrawn while the intestine is again carefully examined.

The procedure is usually well tolerated and rarely causes pain. Many patients even fall asleep during the examination. There may be some discomfort during colonoscopy, but it is usually mild. 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.



What happens after the colonoscopy?

You will be kept in the endoscopic area until most of the effects of the medication have worn off. You may feel bloated for a few minutes right after the procedure because of the air that was introduced while examining the colon.*

You will be able to resume your diet after the colonoscopy unless you are instructed otherwise. If a polyp has been removed, your doctor may wish your diet to be limited before returning to your regular diet.

*After that you may leave, but it is imperative that you be accompanied by a responsible person who can drive you home, since vour coordination mav be impaired for several hours.



Why is colonoscopy necessary?

Colonoscopy is a valuable tool for the diagnosis and treatment of many diseases of the large intestine. Abnormalities suspected by X ray can be confirmed and studied in detail. Even when X rays are negative, the cause of symptoms such as rectal bleeding or change in bowel habits may be found by colonoscopy. It is useful for the diagnosis and follow-up of patients with inflammatory bowel disease as well.

Colonoscopy’s greatest impact is probably in its contribution to the control of colon cancer by polyp removal. Before colonoscopy became available, major abdominal surgery was the only way to remove colon polyps to determine if they were benign or malignant. Now, most polyps can be removed easily and safely without surgery.

Periodic colonoscopy is a valuable tool for follow-up of patients with previous polyps, colon cancer, or a family history of colon cancer.



Are there any complications from colonoscopy and polypectomy?

Colonoscopy and polypectomy are safe and are associated with very low risk when performed by physicians who have been specially trained and are experienced in these endoscopic
procedures.

One possible complication is perforation in which a tear through the wall of the bowel may allow leakage of intestinal fluids. This complication usually requires surgery, but may be managed with anitbiotics and intravenous fluids in selected cases.

Bleeding may occur from the site of biopsy of polyp removal. It is usually minor and stops on its own or can be controlled by cauterization (application of electrical current) through the colonoscope. Rarely, transfusions or surgery may be required. Localized irritation of the vein may occur at the site of medication injection. A tender lump develops, which may remain for several weeks to several 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.