This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition.
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Colonoscopy

Illustration

Having a colonoscopy at the U-M Health System
This guide is for patients who are going to have a colonoscopy. It answers some of the most commonly asked questions. If you have additional questions, talk to your doctor or nurse for more information.

What is a colonoscopy?
A colonoscopy is an examination of the lining of the colon with a lighted, flexible tube about the thickness of your finger. The doctor will insert the tube through your rectum and up through your colon, checking for abnormalities. Often during the colonoscopy, your doctor may perform other minor procedures such as a polyp removal. In addition, if necessary, a small piece of tissue (a biopsy) can be taken for examination in the lab. Please note that biopsies are taken for many reasons and do not necessarily imply cancer.

Possible complications or risks of colonoscopy
Colonoscopy is generally a safe procedure. As wth any medical procedure, however, there are some risks associated with the procedure and with the sedation used.

Perforation and bleeding are the most common of the major complications associated with colonoscopy. Perforation is a tear through the wall of the bowel that may allow leakage of intestinal fluids. Perforations are generally treated with hospitalization, antibiotics, and possible surgery. As mentioned, another possible complication is bleeding, usually at the site of a biopsy or polyp removal. Most cases of bleeding stop without treatment or can be controlled at the time of the procedure. Rarely, blood transfusions or other treatments may be required to stop the bleeding. There is also a risk of having a reaction to a sedative or antibiotic given during the exam. In most cases, medications are available to counteract this reaction.

Although complications after colonoscopy are rare, they can be serious and life-threatening. It is important for you to be aware of early signs that something might be wrong. You should contact your doctor if you feel severe abdominal pain, dizziness, fever, chills, or rectal bleeding after the colonoscopy.

General information
Please contact your primary care physician or insurance company if a referral is necessary before the colonoscopy can be performed.

The colonoscopy will take about 45 minutes, but expect the visit to last from two to four (2–4) hours to allow for preparation and recovery time.

Because you will be sedated you will not be able to drive after the procedure, therefore, YOU MUST ARRANGE FOR A RESPONSIBLE ADULT (OVER 18) TO ACCOMPANY YOU from the endoscopy unit after your colonoscopy. Your procedure will not begin until a responsible adult driver is present on the unit.

This person should remain in the unit during your entire visit so that they are available as soon as you are ready to be discharged. YOU WILL NOT BE DISCHARGED UNLESS THAT PERSON IS IN THE UNIT.

Because your judgment may be impaired after this procedure, YOU WILL NOT BE RELEASED to public transportation, taxicab driver, or even be allowed to walk home without another responsible adult to accompany you.

Complications are rare. However, there are potential complications associated with all medical procedures. These will be explained to you on the day of your colonoscopy before you sign the consent for the procedure.

Be sure to tell the doctor who ordered your test if you are on Coumadin, warfarin, blood-thinners, or any of the anti-platelet medications. You may need special instructions.
Some of the anti-platelets drugs are listed below.

Anti-platelet drugs:

If you have diabetes, you should request an early morning appointment.

For the doctor to see the lining of your colon, it must be free from stool. You will have to take an oral laxative solution (a bowel prep) to clean out your bowel. The health care provider that ordered your procedure will determine which bowel prep is best for you. Specific prep instructions vary, but the prep usually begins 1 to 2 days before your procedure. Please see your prep instructions (given separately) to understand what you should be doing the day before or two days before your colonoscopy to help clean out your bowels for the procedure.

If you have severe heart or liver disease or any kidney disease you SHOULD NOT use the phospho-soda bowel preparation. Also, if you take medicines for blood pressure or heart disease (ACE inhibitors or angiotensin receptor blockers), diuretics (water pills) or certain arthritis medicines (nonsteroidal antiinflammatory drugs—sometimes called NSAIDs) you should not use the phospho-soda preparation unless instructed to do so by your health care provider.

Preparing for the test
If you are unable to keep your appointment, please call 888-229-7408 or 734-936-9250 (option 1) as soon as possible to reschedule.

One week (7 days) before your colonoscopy:
Make arrangements for a responsible adult to accompany you to your colonoscopy appointment.

Do not take iron or herbal supplements for 1 week prior to your procedure.
Contact the health care provider that ordered your test if you are currently taking blood thinners.

Two days before your colonoscopy:
Begin your 2-day bowel prep if that is the prep that you have been given.
If you are unsure whether or not to continue taking the medications you are on prior to this procedure, please ask your nurse or doctor.

The day before your colonsocopy:
Begin your 1-day bowel prep if that is the prep you have been given.

You may eat a normal breakfast. Do not eat solid food after 12 noon.

Drink only clear liquids for lunch and dinner. Do not drink red, orange, or purple liquids, including Jell-O.

Acceptable clear liquids include:

You should have at least 1 to 2 quarts of fluid at midday, another 1 to 2 quarts of fluid in the evening, and again 1 hour before bedtime. You should drink as much fluid as possible, with a goal of 1 to 2 gallons on the day you drink the laxative.

If you are doing a 1-day prep, you should start your first laxative dose between 12 p.m. and 6:00 p.m. the afternoon before the procedure to allow the effects of the prep to be completed by bedtime. See your prep sheet for specific directions.

Prep Links

The day of the colonoscopy
It is important to drink as much clear liquid as possible to keep your body hydrated. You should continue to drink clear liquids, such as water or black coffee, until 2 hours before your colonoscopy. Stop 2 hours before your procedure.

You should take your usual morning medications other than those noted earlier. This is especially important for blood pressure and heart medications. You may take pain medication with a few sips of water up to 4 hours before the test.

Please bring all of the following when you come for your colonoscopy:

Please leave jewelry at home.

Small children will be more comfortable at home.

If you take oral diabetes medications (pills): Do not take the medication the morning of your test. Bring your diabetes medication with you. Please refer to the handout, "Instructions for Patients with Diabetes Having Outpatient Procedures/Tests"

If you take insulin (1 or 2 injections per day): Take one-half (1/2) of your usual morning dose of NPH, Lente or Novolin 70/30 or Lantus insulin and NO Regular or Humalog insulin the morning of your test. If you take evening insulin, follow these same instructions for your dose the evening before your test.

If you take Ultralente insulin or are on 3 or more injections per day, please contact the health care provider who manages your diabetes.

Please refer to the handout, “Instructions for Patients with Diabetes Having Outpatient Procedures/Tests”

The procedure
The colonoscopy will be performed in a room especially designed for endoscopy by a doctor specially trained in gastrointestinal procedures. The doctor who ordered your procedure will make decisions regarding your plan of care.

In the waiting room or preparation area you will be asked questions about your health history, current medicines and allergies. You will also be asked to sign a consent form before the procedure can begin.

After you change into a hospital gown, a nurse will start an intravenous line (IV) that will be used to give you medications to make you more comfortable during the colonoscopy. Equipment that will help the nurse and doctor monitor your heartbeat and breathing will be connected to you.

You will be asked to lie on your left side. You will then be sedated before the doctor passes the lubricated tube into your rectum and colon.  As the tube passes through the curves of your colon, you may feel pressure or discomfort, but you will receive medication throughout the procedure to keep you comfortable. The doctor will put air into your colon in order to see the lining, and you may have some bloating or abdominal discomfort from the air. You may feel as though you have to have a bowel movement.  Pass the air if you feel the need. The doctor will remove as much air as possible after the procedure. 

If biopsy and/or polyp removal is necessary, you should experience no pain.

Recovery
After your procedure you will be taken to the recovery area. One family member may join you there. When you are ready to go home the nurse will discuss instructions and answer your questions. You will be given a summary of findings from your colonoscopy. You may not drive yourself home. A responsible adult will need to be with you when you are discharged from the recovery area.

Be sure to bring a responsible adult, 18 years of age or older, who is a licensed driver with you. Your driver will need to be available in the endoscopy suite before your procedure can begin. You will not be discharged to public transportation or taxicabs unless you have a responsible adult to accompany you.

Post-colonoscopy instructions
You will be given specific written instructions about resuming your medications and diet before leaving the endoscopy unit.

You may return to work or school the day after your colonoscopy.

Do not drive a vehicle or operate machinery for at least 12 hours after your colonoscopy.

Do not make any major legal or financial decisions for at least 12 hours after your colonoscopy.

Do not drink alcoholic beverages for at least 12 hours following your colonoscopy.

U-M Health System Related Sites:
Department of Internal Medicine Division of Gastroenterology
Directions to the Medical Procedures Unit
Instructions for Patients with Diabetes Having Outpatient Tests (on insulin)
Instructions for Patients with Diabetes Having Outpatient Tests (no insulin)


Other Related Web Sites:
NIDDK - Diagnostic Tests - Colonoscopy

Your Digestive System and How it Works

Screening for Colorectal Cancer - see the colonoscopy educational video produced by the American Society for Gastrointestinal Endoscopy


Information provided by UMHS Medical Procedures Unit MPU/MPC staff, August 2009.