Reduce the Mess (and Pain): How to Avoid Vomiting During Colonoscopy Prep

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The worst part about a colonoscopy isn’t the procedure itself. After all, you’re asleep the whole time.

The preparations the night before are the real horror. You have to abstain from eating almost everything you love, take a nasty liquid, and then spend the rest of the night on the toilet. And that’s if you are lucky.

Many people experience severe nausea, vomiting, sweating, and dehydration. And if you have any of those symptoms, you’ll spend hours curled up in the loo, wishing you were dead. 

However, clearing out your digestive system is needed for the process, so the most you can do is try to make yourself comfortable during the prep.

This article looks at how to avoid vomiting during colonoscopy prep. This will help prevent diarrhea and dehydration which can make you feel sicker and even cause complications down the line.

If you want to find out how you can stay as comfortable as possible during a long and painful night of colonoscopy prep, keep reading and follow the tips mentioned below!

How to Avoid Vomiting during Colonoscopy Prep

how to avoid vomiting during colonoscopy prep

Vomiting during colonoscopy prep is common but definitely uncomfortable. Throwing up colonoscopy prep just means you have to drink more of the gross stuff and nobody wants that. It also creates a mess that you have to clean up while you are already weak and exhausted.

These steps will help you avoid throwing up your colonoscopy prep medication and prevent dehydration the night before your procedure. Learn more about list of foods to eat after colonoscopy.

01. Start with Less:

Most people can’t drink colonoscopy prep without gagging. The stuff tastes terrible, so start by drinking a small amount of the medicine. Drinking too much of the prep solution too fast is bound to make you vomit.

Instead, begin with a test dose of the meds. The total dose of the prep is anywhere from 2-4 liters and drinking the entire amount in one go is bound to make you spew. Colonoscopy prep nausea can be avoided by drinking 2 to 3 ounces at first.

Then, wait a little bit. If you don’t experience any vomiting or nausea, drink a larger amount after about 15 minutes.

02. Drink Slowly:

The answer to ‘colonoscopy prep makes me vomit’ is simple. Don’t drink the medicine all in one go. The best way to go about this is to drink it in two doses instead. Each dose should be consumed over 15-30 minutes.

Drink half of the medication the evening before the procedure. The next dose should be taken around 5-6 hours before the procedure itself. 

Bear in mind that this won’t work if your colonoscopy is scheduled early in the morning. You might have to start your prep earlier in that case.

Research has suggested that splitting the dose makes drinking it much more tolerable and does a better job of cleaning out your colon. This, in turn, will give your doctors a clearer view of your insides so that they can identify any anomalies.

03. Take a Break if You Feel Nauseous:

MiraLAX colonoscopy prep side effects include nausea. This is amplified by the fact that it tastes gross and you need to drink a gallon of it. If you feel nauseous, stop drinking the medicine. The same applies if you’ve already started puking.

Giving yourself a break will allow your stomach to settle and let your nausea subside. Once you no longer feel nauseous, start drinking the medicine again in small amounts. Most people find that a 30-to-60-minute break helps them feel much better.

04. Don’t Move Around Too Much:

There’s a good chance that you aren’t going to work out the night before your colonoscopy, or while you wait for the laxatives to take effect. However, you should also avoid things like walking or jogging, bending over, and even housework.

Physical activity can induce nausea and vomiting, especially after you’ve consumed a gallon of fluids. Even something like laundry can feel nauseous in a minute. Instead, lie down, or relax in a half-seated position.

Staying still will prevent the center of your brain that stimulates vomiting from being triggered. A very slight movement, like walking to the bathroom is not a problem. An hour after you’ve taken your final prep dose, you can safely move around again.

05. Chill the Medication:

One way to make your medicine stay down easier is by chilling it in the fridge for an hour. The cold drink will calm your nausea and vomiting and prevent you from feeling too grossed out by the drink.

Besides this, you can also sip on chilled water or Gatorade along with your colonoscopy prep. This will also help prevent nausea/vomiting and make the laxative more effective. Drinking lots of fluids with electrolytes is the best solution to what happens if colonoscopy prep doesn’t work.

06. Take Over the Counter Antiemetics:

Taking simple medication is also a great option, so ask your doctor which ones you can take. Most studies suggest Dimenhydrinate (Dramamine) or Meclizine (Dramamine Less Drowsy) as safe options to prevent vomiting and feelings of nausea.

However, remember that taking Pepto-Bismol will interfere with the colonoscopy procedure, so avoid taking that. Take your antiemetics 15 minutes before your first dose of the colonoscopy prep solution.

Start with a low dose and take something stronger later if needed. Remember to ask your doctor if there are any contraindications, especially if you are on other medications.

07. Talk to Your Doctor:

If you feel extremely nauseous and the steps mentioned above don’t work, call your doctor and ask them what to do. Similarly, if you have severe nausea and vomiting, you are vomiting blood, and think that your nausea will prevent proper colonoscopy preparation, let your doctor know.

How Can I Avoid Dehydration during Colonoscopy Prep?

Avoid Dehydration during Colonoscopy Prep

Between nausea and your semi-permanent position on the porcelain throne, dehydration is a very real possibility. With a colonoscopy prep, how long will diarrhea last is a gamble and will differ for everyone. Some people literally have to spend a couple of hours in the bathroom.

These tips will prevent dehydration and help you replenish the large volume of fluids lost during the preparation stage.

  • During the day, drink 8 glasses of water or other fluids. This will give your body a head-start and go a long way in avoiding dehydration. 

Staying hydrated also prevents the no bowel movement after colonoscopy prep problems some people face.

  • During your prep keep sipping on chilled water or Pedialyte or Gatorade. You can also suck on ice cubes, as this will help soothe nausea as well.
  • Drink water until 2-3 hours before the procedure itself to prevent dehydration.
  • Three days before your procedure, stop consuming hard-to-digest foods like seeds, nuts, and popcorn. 

Instead stick to clear fluids such as:

  • Gatorade
  • Pedialyte
  • Clear broth or stock
  • Coffee and tea without milk or creamers
  • Popsicles
  • Jell-O
  • Clear juices like apple or white grape
  • Carbonated beverages

What Not to Eat before Colonoscopy Prep

You might be wondering about the foods you should stay away from before your colonoscopy. The right diet can also prevent nausea after colonoscopy and reduce the chances of complications during the prep and procedure.

You should avoid all solids for 24 hours before your colonoscopy procedure and stick to the fluids mentioned above.

Avoid these foods for 2-3 days before your colonoscopy:

  • Tough legumes, nuts, seeds, and popcorn
  • Very greasy and fatty foods
  • Chewy and hard cuts of meat
  • Raw vegetables and fruit with peels
  • Whole grains
  • Cruciferous vegetables

Have Any Other Questions?

Here you will find answers to issues people often have about their colonoscopy prep.

01. Is It Normal to Vomit During Colonoscopy Prep?

Some vomiting is normal during a colonoscopy prep, however, avoiding it altogether is a better option.

02. Can I Mix My Colonoscopy Prep with Sprite?

Yes, adding some kind of clear juice or soda will make the prep easier to drink and keep down.

03. What If I Vomit after Taking Suprep?

Give yourself a break and take the prep in two doses.

04. Why is Gatorade Good for Colonoscopy Prep?

Gatorade contains lots of electrolytes and makes up for the ones you lose during the prep.

05. How Long are You Asleep for a Colonoscopy?

You are generally sedated for an hour during the procedure. A colonoscopy takes 20 to 30 minutes and it takes you another 30 minutes to wake up in the recovery room.

06. What Should I Do If I am Still Having Diarrhea Morning of Colonoscopy?

If your colonoscopy prep diarrhea won’t stop, contact your doctor and ask them what to do next, in case you need to reschedule the procedure.

07. During a Colonoscopy Prep, When Does Diarrhea Stop?

This depends from person to person, but it usually does last for a couple of hours.

08. Can I Start Colonoscopy Prep Early in the Evening?

You can start your prep earlier if you plan on splitting the prep into two doses.


The process of cleaning out your colon is painful, gross, and drawn out. However, you need to make sure your colon is completely cleaned out so that the doctors can see what is going on inside.

Knowing how to avoid vomiting during colonoscopy prep can make the whole process much easier to handle. Without any extra nausea and puking, you’ll feel much better and more in control. 

So if you have a colonoscopy scheduled, stock up on the Gatorade and strap in for a long night─ you’ve got this.

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