Key takeaways:
A bowel prep for a colonoscopy removes all the waste from your intestine. This allows for clearer images during the procedure and more accurate results.
Magnesium citrate is one of the most-used medicines to empty your colon before a colonoscopy.
Prepping for a colonoscopy can be unpleasant. But there are steps you can take to help make it better and successful.
Save on related medications
Most people don’t look forward to the bowel prep for a colonoscopy. In fact, many will say that it’s worse than the procedure itself. Magnesium citrate — one of the most common ways to bowel prep — doesn’t taste great. And it can be even more unpleasant when it starts to take effect.
But there are ways to make the prep process go down a little easier. Here, we’ll review the best way to take magnesium citrate before a colonoscopy.
Why do you need to drink magnesium citrate before a colonoscopy?
A colonoscopy is a procedure used to look at the inside of your intestines. Preparing for a colonoscopy requires cleaning out your bowels so that a healthcare professional can see the inside of your intestines more clearly. The goal of preparing for the procedure is to completely clear your bowels of any waste. Magnesium citrate helps to do that.
Magnesium citrate is a kind of laxative that pulls water into your intestine. This not only softens your stool but also increases how often you poop. This means that when you drink a large amount of magnesium citrate — like before a colonoscopy — you’ll be using the bathroom quite frequently.
But before you even prepare for the aftereffects, there are some ways to make the initial drink a little more palatable.
How can you make magnesium citrate taste better?
Magnesium citrate tastes bitter, which can make it unappealing. And, for some people, it makes them feel like they need to throw up. But there are a few tricks that might help.
To drink magnesium citrate without gagging, try:
Chilling the solution in your refrigerator before drinking it
Mixing it with lemon or citrus-flavored drinks like 7UP or Sprite
Drinking something that you like after you drink the magnesium citrate, like coconut water or black coffee
Drinking with a straw to bypass your tongue, which may help lessen the taste
Sucking on mints or menthol lozenges in between sips
Asking your healthcare team for anti-nausea medicine that you can take during your prep
And don’t rush or chug the fluid. Instead, take your time drinking it. If you give yourself enough time to drink it slowly while still allowing it to work, it can help you keep it down.
How long does magnesium citrate take to work?
Magnesium citrate has been shown to work 2 to 4 hours after taking it. By the afternoon or evening of the day before your procedure, you’ll start your preparation process. This is when you’ll first take magnesium citrate.
When to take magnesium citrate for colonoscopy prep
The best time to drink magnesium citrate is usually early in the afternoon on the day before your procedure. This will allow you to drink the magnesium citrate slowly. But this may not be possible with your life or schedule. So some people don’t start the colonoscopy prep until the evening. Both timelines should get you ready in time for your procedure the next day.
You’ll also be asked to drink another bottle of magnesium citrate about 5 to 6 hours before your colonoscopy, on the day of your procedure. This means that if your procedure is scheduled for very early in the morning, you may have to wake up in the middle of the night.
Colonoscopy preparation: We walk you through the details of the procedure and what to expect so you can be prepared.
Want better results? Learn which foods to eat (and avoid) in the days leading up to your colonoscopy to help ensure a cleaner bowel and more accurate results.
Explore your prep options: See the different types of colonoscopy bowel prep kits and how they work so you can talk with your healthcare team about what makes sense for you.
In some cases, people with certain medical conditions like chronic constipation may require an extra day of prep. But your healthcare team can help you determine if you may need a longer prep time.
Do you need to drink the whole bottle of magnesium citrate?
Yes, drink the whole bottle of magnesium citrate if you can. If you’re having trouble finishing it, call your healthcare office to let them know. In this case, they may want to reschedule your procedure.
What else should you do to prepare for a colonoscopy?
There are other things you can do to prepare for a colonoscopy to make it less stressful. To help prepare, try taking the following steps.
3 to 7 days before the procedure
In the week before your colonoscopy, avoid foods that tend to take a longer time to move through the digestive tract. These include foods that are high in fiber like:
Raw vegetables and fruits (especially corn)
Nuts and seeds
Grains, including oatmeal, brown rice, and wheat bread
In addition to modifying your diet, talk with your healthcare team about medications you’re taking. You may need to stop taking certain medications for a period of time before and after your procedure.
And, before you start drinking the magnesium citrate, stock up on moist wipes and diaper cream if you can. These help avoid irritation from wiping after frequent bowel movements.
1 day before the procedure
The day before your colonoscopy, you’ll start a clear liquid diet. Foods and drinks that are allowed include:
Black tea or coffee (no cream or milk added)
Water
Ginger ale
Chicken broth
Apple juice
Light-colored popsicles
Gelatin (Jell-O)
Be sure to avoid red, orange, and purple foods and drinks at this point, because those can be mistaken for blood.
Plan for an evening at home the day before your procedure. This is usually when you start your prep, and you’ll want to be close to a bathroom.
Finally, arrange for transportation to and from your procedure. You’ll need a ride home after receiving anesthesia for the procedure. Having someone drop you off will be better as well, so you can stay as relaxed as possible.
Day of the procedure
The morning of your colonoscopy is when you’ll finish your prep. Avoid eating and drinking 2 to 4 hours ahead of your scheduled procedure. Confirm the actual time frame with your coloscopy office, since some places require a longer window than others.
Frequently asked questions
You can make magnesium citrate easier to drink if you combine it with a liquid that tastes better — like a citrus-flavored soda. It may also be easier to drink if you chill the magnesium citrate first and drink it with a straw.
During your colonoscopy prep, you’re still allowed to drink clear liquids to help satisfy your hunger and stay hydrated. It’s important to check in with your individual food and drink instructions. But most people can still drink things like soup broth the day before their procedure. In some cases, gelatin (Jell-O) is still allowed, which may also be a little more satiating. This may help satisfy hunger more than other liquids, like juice or soda.
The most noticeable effects of magnesium citrate will start within a couple hours of taking it, and you’ll be pooping frequently for about 6 to 12 hours after taking it. But you may be pooping for a day or two more after taking it, until the effect fully wears off.
For most people, bowel movements return to normal in about 2 to 3 days after their colonoscopy. By the following day, you should be able to resume your normal activities.
You can make magnesium citrate easier to drink if you combine it with a liquid that tastes better — like a citrus-flavored soda. It may also be easier to drink if you chill the magnesium citrate first and drink it with a straw.
During your colonoscopy prep, you’re still allowed to drink clear liquids to help satisfy your hunger and stay hydrated. It’s important to check in with your individual food and drink instructions. But most people can still drink things like soup broth the day before their procedure. In some cases, gelatin (Jell-O) is still allowed, which may also be a little more satiating. This may help satisfy hunger more than other liquids, like juice or soda.
The most noticeable effects of magnesium citrate will start within a couple hours of taking it, and you’ll be pooping frequently for about 6 to 12 hours after taking it. But you may be pooping for a day or two more after taking it, until the effect fully wears off.
For most people, bowel movements return to normal in about 2 to 3 days after their colonoscopy. By the following day, you should be able to resume your normal activities.
The bottom line
Preparing for a colonoscopy is an unpleasant process for most people. But there are some steps that you can take to make the process more bearable. If you’re drinking magnesium citrate, you can chill it before drinking it or try adding it to citrus-flavored drinks to help make it taste better. Make sure you have enough time to complete your prep. Also, you’ll want to do it in the comfort of your own home. If you have any concerns about the process, bring them up with your healthcare team. A successful prep makes for a successful procedure.
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References
Brown, A. R., et al. (2004). Bowel preparation for gastrointestinal procedures. Current Gastroenterology Reports.
Caldera, F., et al. (2011). How to avoid common pitfalls with bowel preparation agents. Gastrointestinal Endoscopy.
Hayman, C. V., et al. (2021). Screening colonoscopy: The present and the future. World Journal of Gastroenterology.
Latos, W., et al. (2022). Colonoscopy: Preparation and potential complications. Diagnostics.
Pasricha, T. (2023). Wet wipes and Jell-O: How to prep for your first colonoscopy. The New York Times.
Taylor, E., et al. (2008). Magnesium citrate (Magc) preparation for colonoscopy: Onset and duration of bowel activity. The American Journal of Gastroenterology.
