A colonoscopy is an outpatient procedure in which the inside of the large intestine (colon and rectum) is examined. A colonoscopy is commonly used to evaluate gastrointestinal symptoms, such as rectal and intestinal bleeding, abdominal pain, or changes in bowel habits. Colonoscopies are also performed in individuals without symptoms to check for colorectal polyps or cancer. A screening colonoscopy is recommended for anyone 50 years of age and older, and for anyone with parents, siblings or children with a history of colorectal cancer or polyps.
Colon Cancer Screening
The American Cancer Society recommends that all Americans age 50 and over be screened for colon cancer even if they feel fine. People with a history of colon cancer or colonic polyps in their family may need to be screened at a younger age. In addition, anyone having symptoms such as rectal bleeding, abdominal pain, constipation, diarrhea or weight loss may need to be checked before age 50.
Studies have shown that up to 90% of all cases of colon cancer could be prevented by proper screening. Most colon cancers develop from benign non-cancerous growths called polyps. By undergoing a test called a colonoscopy, polyps can be removed before they develop into cancer. In this manner, colon cancer can be prevented. Colonoscopy is performed as an outpatient procedure. Moderate sedation is given during the procedure so there is little or no discomfort.
What is colonoscopy?
A colonoscopy is an examination of the large intestine. A colonoscope is a long flexible tube about the thickness of a finger which is used during a colonoscopy. This instrument is inserted
into the rectum and then into the large intestine (colon) allowing the physician to examine the lining of the colon. Abnormalities suspected by x-ray can be confirmed and studied in detail. In addition, 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 sample of tissue (a biopsy) for laboratory examination.
What is a polypectomy?
During the course of the colonoscopy, a polyp may be found. Polyps are abnormal growths of tissue which vary in size from a tiny dot to several inches wide. If your doctor feels that the
removal of the polyp is indicated, he or she will attempt to remove it using instruments designed for this purpose.
You should feel no pain during the removal of the polyp. Polyps are usually removed because they can cause bleeding or because they may contain cancer cells. Although most polyps are benign (non-cancerous), a small percentage do contain cancer cells or they are of the type that may, over time, develop into cancer (pre-cancerous polyps).
Removal of colon polyps, therefore, is an important means of prevention and cure of colon cancer—a leading form of cancer in the United States. Any polyps removed during your exam will be checked for cancer by a pathologist.
Are there any complications from a colonoscopy and polypectomy?
Colonoscopy and polypectomy are generally safe. Minimal risks are associated with them when performed by physicians who have been specially trained and are experienced doing these procedures.
One possible complication is perforation of the colon. This is a tear through the intestinal wall allowing intestinal fluids to leak into the abdominal cavity. This is a serious condition that may require surgery, antibiotics, and intravenous fluids at the hospital.
Bleeding may occur from the biopsy site or the site where the polyp was removed. Usually the bleeding is minor and stops on its own. If it continues, it can be controlled by cauterization
(application of electric current) during the colonoscopy. Rarely are transfusions or surgery required.
Infrequently, a localized irritation of the vein may occur at the site of medication injection. A tender lump may develop and remain for several weeks, but it will usually go away with time.
Other possible risks include drug reactions and complications from unrelated diseases, such as heart attack or stroke.