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Preparing For Your Colonoscopy

What is a Colonoscopy?

A colonoscopy is a test that allows your doctor to look at the inner lining of your whole colon, small intestine, and rectum. During a colonoscopy, a doctor uses a thin, flexible, lighted tube with a small video camera attached, called a colonoscope. The colonoscope is inserted into the rectum and entire colon to see if there’s anything unusual, such as:

  • Ulcers
  • Colon polyps (i.e., unusual growths)
  • Tumors
  • Bleeding
  • Inflammation

If anything suspicious is found, your doctor can collect a sample of tissue for further investigation, which is called a biopsy. During the colonoscopy, your doctor can also remove any polyps. Polyps aren’t cancerous but they can develop into cancer.

Colonoscopies are the best way to prevent colon cancer and rectal cancer. You should get screened for colon cancer regularly if you are over the age of 45—or earlier, if you have a family history of colon cancer. Regular screening can also help diagnose colon cancer at an early and treatable stage, giving you more time with the people you love most.

Schedule Your Colonoscopy


You May Be Eligible For a No Cost Screening


How to Prepare for a Colonoscopy

Preparing is just as important as the actual procedure because it impacts how well your doctor can see your colon and rectum. While it may not be your idea of fun, many people say it’s not as bad as you think. And, knowing what to expect ahead of time can help to minimize any inconvenience or concern.

View a how-to guide on preparing for your colonoscopy. 

Click the image below to open in a PDF.

What To Do The Day Before a Colonoscopy

Before a colonoscopy, you will need to clean out your colon with medication and a clear liquid diet. Colon prep can take one to two days, depending on which type of prep your doctor recommends. Plan to stay home during your prep since you may need to use the bathroom often.

Here’s what to do the day before your test.

Drink only clear liquids the entire day. Avoid eating solid food during or after prep. Instead consume clear liquids such as:

  • Water
  • Bouillon
  • Clear sodas, like Sprite or ginger-ale
  • Clear juice, like apple or white grape juice
  • Pulp free lemonade
  • Coffee or tea (without milk or creamers)
  • Plain Jell-O (Avoid red, purple or blue Jell-O, added fruit, or toppings.)

Mix your medication. You will be given a laxative medication ahead of time (e.g. Colyte, Trilyte, Nulytely, or Golytely). Mix the powder in the provided plastic containers with water to the fill line and chill in the refrigerator. Consider adding Crystal Light powdered lemonade to the solution, which may improve its taste.

You’ll need to drink the solution for approximately four hours at the following intervals:

  1. Begin drinking the solution at approximately 6 p.m. the day before your colonoscopy.
  2. Drink one 8-ounce glass every 10 to 15 minutes until you finish half to the gallon. Six hours prior to the procedure, drink the remainder of the gallon (one 8-ounce glass every 15 minutes until done).

You must drink the entire container of the solution. If your stools are not completely clear (pale yellow to clear fluid) after taking the entire solution, you should take one 10-ounce bottle of Magnesium Citrate. This can be purchased without a prescription at any drug store.

After your prep is complete, you may drink water until midnight.

Stop eating or drinking two hours before your procedure. If you are on insulin or other diabetic medication, check with your primary or referring physician for additional instructions.

Talk to your doctor if you are on blood thinners (i.e., Coumadin, Heparin, Lovenox, Plavix, etc.).

What To Do on the Day of a Colonoscopy

You’ve completed prep the day before your test and are ready for your screening. Here’s what to do next.

  • Avoid eating hard candy or chewing gum.
  • Wear comfortable clothing that is easy to remove.
  • Leave jewelry at home.
  • Bring a list of your current medications and allergies.
  • If you are over age 50 and have recently had an electrocardiogram (EKG), bring a copy of the EKG tracing with you or have your primary physician fax a copy.

Registration: Plan to arrive 60 to 90 minutes before our appointment time to complete check-in for your procedure. This is a great time to discuss any concerns or questions with your care team.

Getting ready: Once registered, you will be asked to put on a hospital gown. A nurse will review your medical history and start an intravenous line (IV), which will keep you sedated during the screening.

During the procedure: The procedure will only last 15 to 20 minutes. You will be sedated, so you will be comfortable during your colonoscopy. Your care team will monitor your heart rate, blood pressure, and oxygen levels the entire time.

Recovery: When your procedure is done, you will remain in the recovery room for up to one hour. Your doctor will discuss the results of your procedure with you and give you a written copy of the report.

Returning home: Plan to have a family member or friend drive you home after your colonoscopy. Once you are home, you should drink a lot of fluids and you can eat, but we recommend resting from your normal activities.

You May Be Eligible for a Free Colonoscopy

No insurance? We offer free colon cancer screenings for eligible patients at four convenient locations in the Baltimore region.

  • You may be eligible for a free screening if you are:
  • A Baltimore City, Baltimore County, or Anne Arundel County resident
  • Age 50 or older
  • Under 50 with symptoms or a family history of colon cancer
  • Living on a limited income

Worried that you won’t be able to afford treatment if your doctor finds colon cancer? We’ll help you with resources, including program funds to pay for your diagnosis and treatment. So, all you have to think about is how you want to spend your time with family and friends.

Call to Schedule Your Screening Today


No Cost Screening

To find out if you qualify for a free colon cancer screening,
Call 410-350-8216

Our Locations

MedStar Franklin Square Medical Center
The Harry and Jeanette Weinberg Cancer Institute
9103 Franklin Square Drive
Baltimore, MD 21237

MedStar Good Samaritan Hospital
5601 Loch Raven Boulevard
Baltimore, MD 21239

MedStar Harbor Hospital
The Cancer Center
3001 South Hanover St.
Baltimore, MD 21225

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