Colonoscopy: How to Prepare

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Preparing for your colonoscopy will not only ensure a smooth and successful procedure but help you feel relaxed and calm going into it. Typical preparatory instructions include arranging for a ride home after the procedure, stopping certain medications, and cleaning out your bowels, often with a prescription liquid laxative. While the latter may seem unpleasant, it's an important step that, if skipped, could delay your colonoscopy.

Location

Part of preparing for a colonoscopy is knowing where to go and what you can expect to see once you're there.

The procedure takes about 30 minutes to complete and is usually performed in an outpatient endoscopy center or hospital in a colonoscopy procedure room.

You will be walked or brought there on a gurney. The room may contain large overhead lights, a long and flexible tube (called a colonoscope) connected to a video monitor, and other assorted medical devices located on metal trays.

You will lay down on a procedure table and will have a blood pressure cuff placed on your arm and a probe put on your finger to monitor your heart and oxygen levels during the exam.

What to Wear

On the day of your colonoscopy, you will be advised to: 

  • Shower on the morning of your procedure, but avoid using any skin products including deodorant, perfumes, lotions, creams, and makeup
  • Wear eyeglasses, not contact lenses (if applicable)
  • Leave all jewelry and other valuables at home

Food and Drink

Your healthcare provider will provide you with specific instructions on what you can and cannot eat (and when) prior to your colonoscopy.

Keep in mind, these instructions may vary slightly among providers. Be sure to follow your personal healthcare provider's guidelines.

Generally speaking, dietary instructions for a colonoscopy often include:

  • Starting a low-fiber diet three to seven days before the procedure and avoiding any foods or drinks with red, purple, or blue dyes (which may stain the colon and interfere with the test)
  • Beginning a clear liquid diet the day before the procedure
  • Drinking at least eight glasses of water the day before your colonoscopy to prevent dehydration
  • Not drinking anything for two to four hours before the colonoscopy

Of note, if you are undergoing general anesthesia for your colonoscopy, your healthcare provider will advise you not to eat or drink anything after midnight on the eve of your procedure.

Bowel Preparation

While there are different types of bowel preparations, they all have the same goal—to thoroughly cleanse your bowel so your colon (large intestines) can be best visualized.

You will experience watery diarrhea as a result of this, regardless of the preparation you undergo. With that in mind, be sure you have easy and quick access to a bathroom during this process.

A typical bowel preparation includes drinking four liters of a prescription liquid laxative called Golytely (polyethylene glycol).

Here is an example schedule:

  • Drink half of the Golytely (2 liters) in the late afternoon or early evening the day before the procedure. Your healthcare provider will provide you with specific instructions on how to mix the laxative drink and how to consume it (for example, drink an 8-ounce glass every 10 to 15 minutes).
  • Once you drink half of the Golytely, store the rest in your refrigerator until the morning.
  • On the morning of your procedure, four to five hours before leaving home for the colonoscopy, finish the other half of the Golytely.

It is important to follow your healthcare provider's instructions precisely when completing your bowel preparation.

If you cannot complete the preparation and/or your stool after the preparation is not clear to light yellow in color, your colonoscopy may need to be rescheduled. This also means that you will have to repeat the bowel preparation all over again.

Medications

Prior to your colonoscopy, it's important to tell your healthcare provider all of the medications you are taking, including:

  • Prescription drugs
  • Over-the-counter drugs
  • Supplements, like vitamins or herbal products
  • Recreational drugs

You may be asked to stop taking certain drugs for a designated period of time prior to your colonoscopy. For instance, your healthcare provider will advise you to stop taking any fiber supplements or anti-diarrheal medications three days prior to a colonoscopy.

You will also be advised to stop taking any nonsteroidal anti-inflammatory drugs (NSAIDs), such as Motrin (ibuprofen) or Aleve (naproxen), four to seven days before the procedure.

If you are taking aspirin or other blood-thinning drugs (anticoagulants) like Coumadin (warfarin), or one of the new oral anticoagulant drugs like Pradaxa (dabigatran) or Xarelto (rivaraxoban), your healthcare provider may consult with your cardiologist, primary care provider, or another specialist to determine the best course of action. In some cases, they may decide that it's safer for you to continue a medication based on your individual risks.

What to Bring

Since a colonoscopy is an outpatient procedure, you will be able to go home afterward. You will, however, need someone to drive you home because you will feel groggy from the sedation you receive.

To be best prepared for the day of your colonoscopy, be sure to bring these items with you:

  • Your insurance card and driver's license
  • A list of the medications you take at home
  • Your eyeglasses and their case (if applicable)
  • Loose-fitting (especially around your waistline) clothing to go home in

Pre-Operative Lifestyle Changes

Besides adhering to your healthcare provider's specific diet and bowel preparation instructions, there are some simple practices you can adopt in the days leading up to your colonoscopy:

  • If your bowel preparation involves a prescription, be sure to pick it up well before your procedure date. While at the pharmacy, it's also a good idea to buy some petroleum jelly or wipes with aloe and vitamin E. These can help soothe your bottom after using the bathroom frequently.
  • Since you will be spending a lot of time in your bedroom and bathroom (the day and night before your colonoscopy), have something to read or your favorite music downloaded ahead of time to help keep you occupied.
  • Consider talking with your healthcare provider about ways to make the laxative solution tastier (for example, ask whether you can add lime or a drink mix to it).
  • Plan to take time off work the day of your colonoscopy and the day (or a half-day) before it.
  • If you have children or pets, consider arranging care for them while you are undergoing your bowel preparation.

A Word From Verywell

Being informed about and prepared for your colonoscopy will not only optimize its success, but it will hopefully deflate some of the anxiety that often precedes it—especially if you're getting a colonoscopy for the first time.

Besides engaging in the above practices, do not hesitate to bring up any questions or concerns you have with your healthcare provider.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Colonoscopy. Reviewed October 2019.

  2. Cleveland Clinic. Colonoscopy Test Details. Reviewed October 2019.

  3. Kaiser Permanente. Preparing for your colonoscopy.

  4. University of Connecticut Health. Medications to Avoid for GI Endoscopy Procedures.

  5. Ahmed M. Blood thinners and gastrointestinal endoscopyWorld J Gastrointest Endosc. 2016;8(17):584–590. doi:10.4253/wjge.v8.i17.584

  6. Memorial Sloan Kettering Cancer Center. How to Prepare for Your Colonoscopy Using MiraLAX.

  7. Harvard Health Publishing. Harvard Medical School. Preparing for a colonoscopy. Updated August 2020.