Colonoscopy is the visual examination of the large intestine (colon) using a lighted, flexible fiberoptic or video endoscope. The colon begins in the right lower abdomen and forms a big question mark as it moves up and around the abdomen ending in the rectum. It is 5-6 feet long. The colon has a number of functions including the removal of water from the liquid stool that enters it, so that a formed stool subsequently occurs.
Reasons for the Exam
The colon is the site for numerous diseases which can give you various symptoms. Colonoscopy is useful in discovering these problems and in treating them. Some of these conditions include:
- Colon cancer - This is serious but highly curable if diagnosed early.
- Polyps - These are fleshy tumors which are sometimes the forerunners of colon cancer.
- Colitis (Ulcerative or Crohn's) - Chronic or recurrent inflammation of the colon.
- Diverticulosis - These are little sacs that develop on the colon wall. They can become infected or be a cause of bleeding.
- Sites of bleeding
- Abdominal pain
- Abnormal barium X-ray exam
- Chronic diarrhea
The colonoscope is a flexible instrument that can be steered around the many bends in the colon. The colonoscope has an optically sensitive chip in its tip that transmits an image on a large video screen. An open channel in the scope allows other instruments to be passed through it in order to perform biopsies, remove polyps or inject solutions.
Benefits and Alternative Testing
The benefit of a colonoscopy is that it allows the doctor to make a diagnosis and correct problems during the examination. For example, if a polyp is found during the exam, it usually can be removed at that time, eliminating the need for surgery or another bowel preparation later. If a bleeding site is identified, treatment can also be administered to stop the bleeding during the procedure. Biopsies can also be taken to diagnose potential problems.An alternative to a colonoscopy is a combination of a barium enema, which is an X-ray test of the colon, and a flexible sigmoidoscopy, which is a test similar to a colonoscopy that examines only the last 1 to 2 feet of the colon. A bowel preparation is required for both tests but there is usually no sedation. The barium enema does not allow biopsies to be taken or polyps to be removed. If polyps are found, a colonoscopy would be needed.
Side Effects and Risks
- No test is 100% accurate and infrequently colonoscopy can miss abnormalities that are present. Colonoscopy is a very safe procedure and complications are very uncommon. Minor complications that may occur include:
- A temporary feeling of bloating.
- Bleeding after a biopsy or removal of a polyp. Bleeding is generally minimal and rarely requires blood transfusion or surgery.
- Oversedation occurs infrequently and almost always can be reversed.
- A localized irritation of the vein can occur at the IV site resulting in a tender lump that may last for several weeks.
- Application of hot moist towels 3-4 times a day may relieve the discomfort.
- More serious and even less frequent complications include:
- Complications of underlying heart or lung disease.
- Reactions to one of the sedatives.
- Perforation (a tear in the colon) is exceedingly rare and occurs in less than one in 1,000 cases.
- Hemorrhage (bleeding) requiring transfusion.
- Any of these complications could involve hospitalization, emergency surgery, or in an exceptionally rare case, death.
Preparation begins before the day of your scheduled appointment. Your colon must be empty during colonoscopy so that the doctor's view is not blocked by particles of stool. This requires a special diet and laxative preparation the day before the test. There are several laxative preparations available. The preparation selected for you is based on your medical history, age, and other factors.
Click below to view the Colonoscopy Preparation instructions.
- If you are on blood thinner medication, such as Coumadin or Warfarin, it is important to let us know well in advance of your appointment. If you are currently taking these medications and have not already given that information to our office, please call immediately. A nurse will contact you about instructions about taking your Coumadin prior to this procedure.
- YOU MUST HAVE SOMEONE TO DRIVE YOU HOME OR THE DOCTOR WILL NOT DO THE PROCEDURE. If your driver does not plan to stay during your procedure, you will need to provide a phone number where that person can be contacted.
- Using a small amount of water, take your prescription medications as you usually do unless you have been instructed to "hold" the medication prior to the procedure. It is very important that you take your blood pressure or heart medication as usual.
- Bring a list of your current medications and any allergies to medication.
- Bring your insurance cards with you.
- If you are a diabetic, check your blood sugar at home before your procedure.
- If you have an implanted cardiac defibrillator, it is very important that you bring the card identifying the device manufacturer, model and serial number.
- You may wear your glasses, dentures or hearing aids. It is best to leave your jewelry at home.
Before the Procedure
When you arrive for your colonoscopy, a brief medical history will be reviewed with you by a nurse. Please bring a list of your current medications and any allergies to medications. You will be asked to remove your clothing and change into a patient gown.
An intravenous (IV) catheter will be placed in your hand or forearm so that medication can be given for sedation. Most of the effects of the sedation last for 15-60 minutes, and you may not be able to recall the procedure afterwards. Once you are relaxed, you will be positioned on your left side on a stretcher. Lubrication will be applied to the rectal opening. The colonoscope will then be inserted and advanced through the colon. The procedure will take about one half hour. To improve visualization, air will be instilled into the colon. This may cause a feeling of fullness and slight cramping. If a polyp is found, it can usually be removed. Biopsies may be taken and sent for analysis.
After the Procedure
You will remain in the recovery room area for one-half to one hour after the procedure depending on your vital signs and level of consciousness. You may feel bloated from the air used during the procedure. The medication given to you during the procedure may affect your reflexes and judgment. You should not drive a car, operate machinery, or make any legally binding decisions for the remainder of the day.
Following the exam, your physician will discuss the results with you and your family. If you want family members to hear the results of your test, they should remain in the waiting area for the duration of your stay.
Answers to Common Questions
Please visit our Common Questions page.
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