Colonoscopy

Colonoscopy is the visual examination of the large intestine (also known as the colon) using a lighted, thin flexible instrument. The instrument is approximately 6’ long with a steerable end to direct its safe passage through the colon. The lighting system uses fiberoptics, or more commonly, a video computer chip to produce an image that may be watched on a video screen monitor.

Normal Transverse Colon

A colonoscopy allows for accurate and safe direct inspection of the inner lining of the colon as a diagnostic instrument. A channel through the middle of the scope permits insertion of other instruments to enhance the capabilities of the colonoscopy. A biopsy may be taken by passing a biopsy forceps onto a particular area of the colon that is being examined. With a small pinch, tissue is removed with this device. The tissue is then sent to the pathology lab for microscopic examination. The result of these biopsies are available several days after the colonoscopy procedure. Material (i.e. a stool specimen) can be collected from the inside of the colon for examination for infections or parasites, when appropriate.
 

Treatment modalities may also be applied. A polyp is a growth within the colon that can be a precursor to colon cancer. When polyps are detected at the time of colonoscopy, they can often be removed by passing a wire snare through the channel of the colonscope and grasping the base of the polyp where it attaches to the colon wall. An electrical current is then applied to simultaneously cut the polyp free and to cauterize the site to minimize the risk of bleeding. The polyp tissue is then removed and sent to the pathology lab for microscopic examination (please see section on Colon Cancer and Colon Polyps).

Day before the Colonoscopy

You will take laxatives to cleanse the colon in preparation for the examination. Please refer to instructions given to you by your doctor. Additional information and preparation instructions are also available on our website. Please see Procedures and choose the prep your doctor has selected for you.

Day of the Examination

On the day of the examination you will need to arrive on an empty stomach, not having eaten or drank since midnight the night before. You may take your usual medications with sips of water. If you are taking Aspirin or medications for diabetes, you will need specific recommendations regarding these medications. If you are taking other blood thinners, such as Coumadin, please make sure to notify us at least a week before your test.

When you arrive for your colonoscopy, you will be asked to fill out the appropriate paperwork and then change into an examination gown. The nurse will ask additional questions regarding your history and medications and an I.V. will be started in your arm to provide I.V. fluids and medication for sedation. You will then be brought into the room where the test will be performed. A blood pressure cuff will be placed on your arm and an oxygen sensor on your finger, so that your vital signs can be carefully followed throughout the procedure.

Usually Versed (a medication similar to Valium) and Demerol (a narcotic pain medication) are used. If you have a history of allergies or sensitivity to either of these, please let us know ahead of time. The level of sedation of these medications results in "twilight sleep," or what is also referred to as "conscious sedation." While under the influence of the medications, you can breathe on your own and most patients can even talk and respond adequately to simple requests, such as turning or moving during the examination. After the test, most patients realize that they have little to no recollection of the time spent under the sedation, thus causing a brief amnesia effect.

The colonoscopy itself usually lasts about 20-30 minutes. You will rest in the recovery area following the procedure. The recovery period is usually between thirty and sixty minutes. For the rest of the day, light activity is recommended and driving is strictly prohibited. YOU MUST HAVE A DRIVER TO DRIVE YOU HOME AFTER THE COLONOSCOPY - THIS IS MANDATORY.

Results

If no biopsies are needed, then the results of the examination can be given to you that day. Due to the sedative medications and amnesia effect, it is preferable to have someone with you with whom the results can be discussed that day. Biopsy results are generally available within one week and may be discussed in the office or by telephone. If at any time you have any questions regarding your test or its results, we encourage you to call us directly for additional explanation and information. We prepare a typewritten report for your primary physician and any other physicians that need a copy of the report for your files. A copy of any biopsies obtained are also sent with our typewritten report.

Benefits of Colonoscopy

A colonoscopy is performed to diagnose and/or treat many problems within the colon. Colonoscopy is felt to be, in almost all circumstances, "the gold standard test" given its high degree of accuracy. As discussed above, if a lesion or polyp or other abnormalities are found, colonoscopy can also obtain additional specimens for biopsy and other examination, that is, it has the ability to "treat" and not "just look." If there is a bleeding site identified, treatment can be given at that time to attempt to stop the bleeding. Other treatments (i.e. laser) are also available in specific circumstances.

Alternatives to Colonoscopy

Alternative tests to colonoscopy include Barium Enema (also known as lower GI X-ray) examination of the colon. Stool specimens can be examined for the presence of problems, such as blood or infection. Flexible sigmoidoscopy is similar to colonoscopy, but the examination is limited to approximately the lower one-third of the colon (large intestine). No I.V.’s or sedatives are usually given for these examinations. "Virtual colonoscopy" is an X-ray technique using CT or MRI to image the colon. In its  current form, it does not appear as sensitive to finding colon polyps as colonoscopy. If a lesion or polyp is seen, it can not be biopsied nor removed with this technique - the patient would then need colonoscopy to directly examine the colon and perform biopsy or removal. Virtual colonoscopy requires an extensive bowel prep.

Side Effects and Risks of Colonoscopy

During the colonoscopy, air is used to inflate the colon to improve visualization. Prior to completion of the test, as much air as possible is suctioned out but usually cannot be completely removed. This may lead to some bloating, distention and/or discomfort after the procedure. The passage of gas after colonoscopy is often encouraged and lessens any discomfort. Serious risks with colonoscopy are uncommon (less than one in one thousand) but can include bleeding, perforation (making a hole in the bowel), infection or a reaction to one of the sedative medications. A diagnostic error or oversight can rarely occur. Other risks include a complication from an unrelated disease such as heart attack or stroke; death is extremely rare, but remains a remote possibility.

Informed Consent

This is an example of the informed consent statement that you will be asked to read and sign at the time of colonoscopy.

Consent for Medical Procedure and Acknowledgement of Risk Information for Colonoscopy

Nature and Purpose of Procedure: I understand that current medical practice requires my prior informed consent and acknowledgment of risk information before proceeding with any medical procedure. Colonoscopy consists of the passage of a flexible lighted tube (endoscope) through the rectum and into the colon to closely examine the lining of the large intestine. Usually intravenous sedation is given to minimize the possibility of discomfort Due to this sedation, I understand that I will be unable to drive and must have someone with me to drive me home. I necessary, a very small piece of tissue will be taken to send to the laboratory for analysis; if a polyp is seen, it may be removed through the endoscope.

Reasonably Known Risks Associated with Colonoscopy: The procedure is generally considered to be of low risk. Some, but not all, of the known risks include the following: a localized irritation of the vein may occur at the site of intravenous injection of medication; a tear in a blood vessel, or in the wall of the colon itself, may occur; this could lead to bleeding or leaking of intestinal contents into the abdominal cavity; the bleeding usually stops on its own but could require transfusion or surgery; a tear in the wall of the gastrointestinal tract may seal over by itself but would require an operation if leakage of intestinal contents occurred. Other risks include an adverse reaction to a medication or a complication from an unrelated disease such as heart attack or stroke; death is extremely rare, but remains a remote possibility.

Authorization: I authorize Dr (s) ______________________ and his/her (their) associates or assistants to perform the above mentioned procedure to the extent deemed necessary. I understand that during the course of the procedure, unforeseen conditions may become apparent which would require an extension of the original procedure or even a different procedure; I authorize the above-named physician(s) to perform such procedures or transfer to a hospital as deemed necessary and advisable in the exercise of his/her (their) professional judgment.

Alternative Procedures: Although colonoscopy is considered a safe and accurate way to examine the gastrointestinal tract, other procedures may be available to you, and usually include x-rays and/or surgery. These may be discussed with you by your physician as deemed appropriate to your individual case. If you have any questions or concerns about alternative procedures or risks, you are encouraged to discuss those with your physician prior to signing this consent.

Consent and Acknowledgment: By signing this form, I acknowledge that I have read and understand this consent form and have received sufficient information regarding colonoscopy to give my informed consent. I understand that I may at any time request more detailed information of any other and less likely problems or complications. I am aware that the practice of medicine is not an exact science and that the nature of the procedure, anticipated results, and potential complications cannot always be anticipated with complete accuracy. For this reason, I acknowledge that prior to signing this form I understand this information and I have been given a complete opportunity to ask any and all questions of my physician, which I may wish answered concerning the procedure, its risks, and alternative procedures.

Related Sites

American Gastroenterological Association, http://www.gastro.org
National Digestive Diseases Information Clearinghouse (NDDIC), http://digestive.niddk.nih.gov

Ohio Society of Gastroenterology Nurses and Associates, http://www.osgna.org