What is a colonoscopy?
A colonoscope is a long, flexible instrument, about the width of the index finger, that has a video camera and a bright light built into it. It allows a physician to place it within the bowel and closely examine the lining of the colon and rectum. This is performed by introducing the colonoscope into the rectum and then advancing it to the beginning of the colon (large intestine). The scope is then removed slowly to obtain a good view of the lining of the entire large bowel.
Why is a colonoscopy performed?
A colonoscopy can be performed for various reasons including routine cancer screenings, evaluation of bowel pattern or colon lining changes and rectal bleeding. It can also be useful in evaluating a patient before or after surgery and in follow up care of a person with known colon polyps or prior polyp removal.
What preparation is required?
The colon must be cleansed prior to the exam so that the physician has a clear view of the intestinal lining. This is usually performed 1-2 days before the examination. There are several common methods of preparing the colon including the use of special cleansing solutions, laxatives and enemas. Specific instructions regarding bowel cleansing will be given at the time of scheduling.
In addition to taking this medication, you will be asked to eat only clear liquids (water, soda, tea, broth, juice without the pulp, Jell-O, popsicles) for the 24 hour period before the examination. Follow your physician's instructions carefully. If you do not complete the preparation, it may be unsafe to perform the colonoscopy and the procedure may have to be rescheduled. If you are unable to take the preparation, contact your physician.
Discuss your medication regimen with your physician. Medications such as Aspirin, Motrin, Ibuprofen and other anti-inflammatory drugs will need to be discontinued 5-10 days before the examination. It is essential that you alert your surgeon if you require an antibiotic prior to undergoing dental procedures, since you may also require antibiotics prior to colonoscopy.
You will be sedated with intravenous medication during the procedure so that there is little or no discomfort. Arrangements to have a responsible adult accompany you to and from your appointment are mandatory due to the sedation. The sedatives will affect your judgment and reflexes for the rest of the day. You should not drive, operate machinery or sign important legal documents until the next day.
What can be expected during a colonoscopy?
Medication will be given intravenously to help you relax. You will be lying on your side or your back while the colonoscope is advanced through the colon. The lining of the colon is examined carefully while inserting and withdrawing the instrument. The procedure usually lasts 15-20 minutes. In rare instances, the entire colon cannot be visualized due to incomplete bowel cleansing, anatomy or patient intolerance of the procedure.
What if the colonoscopy shows an abnormality?
If your surgeon sees an area that needs a more thorough evaluation, a biopsy may be obtained and submitted to the laboratory for analysis. This is done by placing a special instrument through the colonoscope to sample the lining of the colon. Polyps are generally removed. The majority of polyps are benign (non-cancerous), but that cannot always be determined by appearance alone. Rarely polyps or small cancers can be missed. Polyps can be removed by fulgurating (burning) or by snare (wire loop). It may take your surgeon more than one sitting to do this if there are numerous polyps or if they are very large. Sites of bleeding can be identified and controlled by injecting certain medications or coagulating (burning) the bleeding vessels. Biopsies do not imply cancer; however, removal of a colonic polyp is an important means of preventing colo-rectal cancer.
What happens after a colonoscopy?
Mild abdominal cramping or bloating may be experienced after the procedure. These sensations can be attributed to air that was introduced into the colon during the exam. This should quickly improve with the passage of the gas. It is also encouraged to drink plenty of fluids and resume a light diet for the rest of the day. You may return to your normal diet, as tolerated, the next day.
Due to the effects of sedation, you may feel very tired and disoriented. It is recommended that you go home and rest for the remainder of the day. Your surgeon will talk to you about the procedure and give you post-procedure instructions. If you forget what was discussed, please call your surgeon's office the following day.
If polyps were found during your procedure, you will need to have a repeat colonoscopy. Your surgeon will determine the frequency of your colonoscopy exams.
What complications can occur?
Colonoscopy and biopsy are safe when performed by surgeons who have had special training and are experienced in these endoscopic procedures. Complications are rare, however, they can occur. They include, but are not limited to, bleeding from the site of a biopsy or polypectomy and a tear (perforation) through the lining of the bowel wall. Should this occur, it may be necessary for your surgeon to perform abdominal surgery to repair the intestinal tear. Another complication could be a reaction to the sedatives used during the procedure. Irritation to the vein that medications were given is uncommon, but may cause a tender lump lasting a few weeks. Warm, moist towels will help relieve this discomfort. Blood transfusions are not common, but could be required. Bleeding can occur for several days after a biopsy. However, you should notify your physician if you have rectal bleeding in excess of one-half cup. It is also important to contact your surgeon if you notice symptoms of severe abdominal pain, fever, or chills.