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Colonoscopy

How To Prepare

Before you have a colonoscopy, tell your doctor if you:

  • Are taking any medicines, such as insulin or medicines for arthritis. Check with your doctor about which medicines you need to take on the day of your test.
  • Are allergic to any medicines, including anesthetics.
  • Have bleeding problems or take aspirin or other blood thinners.
  • Had an X-ray test using barium, such as a barium enema, in the last 4 days.
  • Are or might be pregnant.

You may be asked to stop taking aspirin products or iron supplements 7 to 14 days before the test. If you take blood-thinning medicines regularly, discuss with your doctor how to manage your medicine.

You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

Arrange to have someone take you home after the test, because you may be given a medicine (sedative) to help you relax before the test.

Colon prep

Before this test, you will need to clean out your colon. The following information gives you a general idea of the preparation for a colonoscopy. Your doctor will give you specific instructions before your test.

  • One to two days before a colonoscopy, you will stop eating solid foods and drink only clear fluids, such as water, tea, coffee, clear juices, clear broths, flavored ice pops, and gelatin (such as Jell-O). Do not drink anything red or purple, such as grape juice or fruit punch. And do not eat red or purple foods, such as grape ice pops or cherry gelatin.
  • Your doctor will recommend a medicine for you to use to prepare for your colonoscopy. It will most likely be a prescription laxative tablet and/or a laxative solution (such as Nulytely or Golytely) that you drink before your colonoscopy. This solution will be given to you as a powder that you will mix with 1 gal (3.8 L) of water. You may need to drink this laxative solution over 1 to 2 hours in the evening before the test. Or you may be asked to drink half the solution the evening before your test and the other half the morning of your test. This solution may taste very salty and may make you feel sick to your stomach. To make your colon prep easier, you may want to try some of the following tips:
    • You may find it easier to drink the solution if you use a straw with the end at the back of your throat (to bypass the taste buds).
    • Each time you drink some of the solution, you may also drink some water or clear fluids (like apple juice) to help get rid of any unpleasant taste in your mouth.
    • Ask your doctor if it is okay for you to add flavored drink crystals (such as Crystal Light) to the solution.
    • Add lemon juice to the solution or suck on sliced lemon wedges after you take a drink.
    • You may find it easier to drink the solution if you chill it in the refrigerator first.
  • Your doctor may recommend a different preparation product, such as the Nutraprep meal kit or sodium phosphate tablets (for example, Visicol). These are other methods of preparing for a colonoscopy. If you are concerned about the standard bowel prep, you can ask your doctor whether another method will work for you.
    • Oral sodium phosphate (either tablets or liquid) can cause kidney problems. Make sure you check with your doctor before using a nonprescription sodium phosphate product.
  • You will want to stay home while doing the colon prep, because the colon prep will make you use the bathroom often.
  • Drink plenty of clear fluids during the prep so you will not get dehydrated. This will also help clean out your colon completely after you finish the colon prep.
  • Do not eat any solid foods after doing the colon prep.
  • Stop drinking clear liquids 6 to 8 hours before the colonoscopy.

WebMD Medical Reference from Healthwise

Last Updated: October 30, 2013
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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