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 – bowel prep – 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 through regulated bowel movements 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!

What Is Colonoscopy?

Reduce the Mess (and Pain): How to Avoid Vomiting During Colonoscopy Prep 1
110405-N-KA543-028 SAN DIEGO (April 5, 2011) Hospitalman Urian D. Thompson, left, Lt. Cmdr. Eric A. Lavery and Registered Nurse Steven Cherry review the monitor while Lavery uses a colonoscope on a patient during a colonoscopy at Naval Medical Center San Diego. (U.S. Navy photo by Mass Communication Specialist 2nd Class Chad A. Bascom/Released)

Colonoscopy is a medical test where the doctor uses a flexible fiber-optic instrument with a camera at the end to see inside your colon or large intestine. The colonoscope is inserted through the anus and the doctor takes a look through a video monitor.

A colonoscopy is done to check for irregularities in your colon like polyps, swollen or irritated tissues, or cancer.

Why Do You Need Colonoscopy Prep?

Colonoscopy prep is essential to ensure your intestines have no stool inside as that would block a clear view of your colon. If the doctor can’t see any growth or polyps in your colon, the test results won’t be accurate, and worse, you’ll need to do the procedure again.

The bowel prep will help you induce bowel movements to clear out your bowels before you go for the colonoscopy. That’s why you need colonoscopy prep to ensure the doctor gets a proper view of your intestine.

What Should You Do A Week Before Colonoscopy Prep?

Colonoscopy prep is not only about what to do right before or during the prep stage. There are other factors you should take care of one week before the procedure.

  1. Make sure you have someone to drive you home safely after the procedure.
  2. While you’re in the doctor’s office, ask which medications you need to stop taking before you drink colonoscopy prep. You may need to temporarily discontinue or change the dosage of blood thinning and diabetes medications. So, share your medical history with the doctor for proper guidance.
  3. Bowel preparation is necessary as there will be frequent bowel movement. So stock up on toilet paper, clear sports drinks, and Vaseline. You can apply Vaseline to the sore parts of your anus to get relief.

How to Avoid Vomiting during Colonoscopy Prep

Reduce the Mess (and Pain): How to Avoid Vomiting During Colonoscopy Prep 2
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
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.

Reduce the Mess (and Pain): How to Avoid Vomiting During Colonoscopy Prep 3
What Not to Eat before Colonoscopy Prep 1

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

What To Eat After Colonoscopy

During the colonoscopy prep, you had to drink the bowel prep solution to induce bowel movements that got rid of almost all the fluids from your body. Your solid diet was also restricted to a large extent.

Now that the procedure is over, you need to take it easy as your digestive system won’t be ready yet to accept greasy or rich foods.

It’s best to eat very little or not at all for a few hours after the procedure. Your doctor will most likely advise you to be on a fluid-based diet or a low fiber diet that consists of foods that are easy to digest.

What To Eat After Colonoscopy
What To Eat After Colonoscopy

Here’s a list of what to eat after colonoscopy:

  • Drinks that contain electrolytes like Gatorade
  • Water
  • Vegetable juice
  • Fruit juice
  • Herbal tea
  • Soup
  • Clear broth
  • Graham crackers
  • Saltine crackers
  • Scrambled eggs
  • Tofu (if you’re not allergic to soy)
  • Baked or mashed potato
  • Soft, cooked vegetables
  • Yogurt
  • Popsicles
  • Jell-O
  • Canned peaches and other tender fruit
  • Pudding
  • Soft white fish
  • White bread without seeds
  • Smooth nut butter
  • Apple butter

What NOT To Eat After Colonoscopy

Here’s what you should NOT eat after colonoscopy.

  • Nuts
  • Alcoholic drinks
  • Fried food
  • Steak or any tough meat
  • Seeded bread or whole grain bread
  • Chunky nut butter
  • Seeded or whole grain crackers
  • Coconut
  • Corn
  • Brown rice
  • Spicy and seasoned foods
  • Raw veggies
  • Legumes
  • Popcorn
  • Raisins and other types of dried fruit
  • Unpeeled fresh fruit

Understanding Colonoscopy: Procedure, Preparation, and Results


During the colonoscopy procedure, the patient is typically sedated or given anesthesia to minimize discomfort. The doctor inserts the colonoscope into the anus and advances it through the rectum and colon. The colonoscope inflates the colon to allow the doctor to view its lining clearly. If the doctor sees any abnormalities, such as polyps or tumors, they may take a tissue sample for further analysis. The procedure usually takes between 30 minutes to an hour, depending on the findings and the patient’s condition.


Preparation for colonoscopy is essential for accurate results. The doctor will provide detailed instructions on how to prepare, which typically involves a strict liquid diet for one or two days before the procedure. The patient must also take a laxative solution or pills to empty the colon fully. It’s crucial to follow the preparation instructions carefully to ensure the colon is entirely clear for the procedure. Failure to do so may result in a need for a repeat colonoscopy.


After the procedure, the patient will be monitored for a short period until the sedation or anesthesia wears off. The doctor will provide the initial results of the procedure and discuss any abnormalities found. If a tissue sample was taken during the procedure, the results may take several days to weeks, depending on the laboratory processing time. If the doctor found any abnormalities, such as polyps, they may recommend follow-up testing or further treatment.

Benefits and Risks

Colonoscopy is a valuable tool for detecting and preventing colon cancer. It is recommended for individuals aged 45 years and older or those with a family history of colon cancer. However, like any medical procedure, colonoscopy has risks, such as bleeding or perforation of the colon. These risks are relatively rare but can occur, particularly in high-risk patients. It’s essential to discuss the benefits and risks of colonoscopy with your doctor before undergoing the procedure.

What to Watch for and What to Do

Colonoscopy is a common medical procedure used to diagnose and treat various gastrointestinal conditions. While colonoscopy is generally considered safe, complications can occur during or after the procedure.


Bleeding is a potential complication of colonoscopy that can occur during or after the procedure. Mild bleeding is relatively common and usually resolves on its own. However, severe bleeding can occur in rare cases and may require treatment, such as blood transfusion or surgery. Symptoms of bleeding may include blood in the stool, dizziness, or weakness. If you experience these symptoms, contact your doctor immediately.


Perforation, or a tear in the colon, is a rare but potentially life-threatening complication of colonoscopy. It can occur during the procedure if the colonoscope punctures the colon’s wall. Symptoms of perforation may include severe abdominal pain, fever, or nausea. If you experience these symptoms, seek medical attention immediately.

Adverse Reaction to Sedation

Sedation or anesthesia is typically used during colonoscopy to minimize discomfort. However, some patients may experience adverse reactions, such as allergic reactions or respiratory problems. Symptoms may include difficulty breathing, wheezing, or swelling of the face or tongue. If you experience these symptoms, notify the medical staff immediately.


Infection is a rare but potential complication of colonoscopy. It can occur if the colonoscope or other instruments used during the procedure are not properly sterilized. Symptoms of infection may include fever, chills, or redness or swelling at the site of the procedure. If you experience these symptoms, contact your doctor immediately.

Bowel Preparation Complications

Bowel preparation is an essential part of colonoscopy, and complications can occur if the instructions are not followed correctly. These complications may include dehydration, electrolyte imbalances, or nausea and vomiting. Symptoms may include dry mouth, dizziness, or abdominal pain. If you experience these symptoms, contact your doctor immediately.

Have Any Other Questions?

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

Is It Normal to Vomit During Colonoscopy Prep?

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

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.

What If I Vomit after Taking Suprep?

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

Why is Gatorade Good for Colonoscopy Prep?

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

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.

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.

During a Colonoscopy Prep, When Does Diarrhea Stop?

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

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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