5 Foods and Drinks to Avoid While Taking Miralax

Miralax (polyethylene glycol) is an over-the-counter (OTC) laxative that can relieve constipation. Miralax is an osmotic laxative, which means it draws water into the bowels. This makes stool softer and easier to pass. Miralax also increases the overall size of stool in the bowels. This can trigger bowel contractions, which can stimulate a bowel movement.

Like any medication, Miralax can cause side effects like:

• Bloating

• Gas

• Diarrhea

• Stomach cramps 

Some foods and drinks can affect how well medications work or worsen medication side effects. There aren’t any foods that interact directly with Miralax. But, certain foods and drinks can worsen constipation, making Miralax less effective. Some foods and drinks can also worsen side effects from Miralax, which makes it harder to stick with treatment.

Here are five foods and drinks to avoid while taking Miralax so that you get the best results from your medication while minimizing side effects.  

1. Alcohol

Laxatives work best when people drink plenty of fluids and stay well hydrated. Miralax is no exception. 

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While water is usually the best drink for staying hydrated, you can drink other fluids, too. But alcohol is not a good option. Unlike other fluids, alcohol makes you pee, which leads to dehydration.

Miralax works by drawing water into the bowels. If you’re dehydrated, you’ll have less water in your body for Miralax to use. If you drink alcohol, you may not get the full effects of your Miralax dose. 

Plus, alcohol can also trigger diarrhea. Since Miralax can also cause diarrhea, combining the two may lead to loose stools.

Avoid drinking alcohol while taking Miralax so you get the full benefits of the medication.    

2. Fried and fatty foods

You may already know that high-fat foods can affect your heart health. But did you know that fatty foods can also affect how well your gut functions? 

Fats can cause the stomach to empty more slowly. If you eat fatty foods around the same time you take a dose of Miralax, it will take longer for your medication to reach your intestines. This will delay how quickly you see results from Miralax. 

EXPERT PICKS: WHAT TO READ NEXT

• Can kids take Miralax? Yes, Miralax is safe for kids who are constipated. 

• How quickly can you expect results? Our experts review how long it takes for Miralax to work for constipation. 

• The right hydration is key if you’re constipated. Here are the best drinks for constipation.

High-fat foods also tend to have less fiber. Not getting enough fiber can worsen your constipation. You may not get the same results from Miralax if your constipation gets worse. You may need to take more Miralax or take it for a longer period of time in order to get relief. 

Limit high-fat foods while taking Miralax. Some examples include:

• Fried foods like french fries or fried chicken

• Greasy foods like pizza, cheeseburgers, and donuts

• Fast foods

3. High-fiber foods

You want to avoid very high-fiber foods while taking Miralax. This may be a surprise. Most people who experience constipation are constantly hearing that they should eat more fiber.  

Fiber does prevent constipation, but too much fiber can cause gassiness and bloating. Miralax can lead to these symptoms, too. So too much fiber can worsen Miralax side effects. 

You want to include some fiber in your diet but not too much. Most people can get the right amount of daily fiber (25 g for women and 38 g for men) by eating four or five servings of fruits and/or vegetables daily. Limiting your fiber intake to less than 50 g each day will help you avoid unpleasant gut symptoms. 

4. Dairy

Many people notice that their constipation gets worse if they eat dairy products. 

Dairy products are low in fiber. So if you eat a lot of dairy, you’re less likely to have room for fiber-rich foods. This can worsen constipation and make it harder for Miralax to work. So you may want to limit your dairy intake until your constipation is under control.

Lactose and milk proteins have also been linked to constipation in some people. 

People who are lactose intolerant may be more familiar with symptoms like bloating and diarrhea. But up to 30% of people with lactose intolerance develop constipation. 

Children who can’t tolerate or are allergic to milk proteins develop gut changes that can also lead to constipation. 

You may want to avoid dairy if you’re lactose or milk-protein intolerant. This may help Miralax work better and help you avoid unpleasant side effects. 

5. Sugary foods and drinks

Studies show that people who eat a lot of high-sugar foods experience more constipation. This is likely because foods high in refined sugars are also low in fiber. People who eat high-sugar foods are less likely to have room for fiber-rich foods. This can worsen constipation, which can lower Miralax’s effectiveness.

Sugary foods and drinks also tend to be higher in calories. Several studies found that high-calorie meals cause the stomach to empty more slowly. If you eat sugary foods around the same time you take a dose of Miralax, it will take longer for your medication to reach your intestines. This will delay how quickly you see results from Miralax. 

Also, high sugar intake can trigger diarrhea. Miralax can also cause diarrhea. Combining the two increases your risk of experiencing this side effect. 

Examples of high-sugar foods include:

• Candy

• Donuts

• Soda

• Packaged baked goods

• Juice and other sweetened beverages

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Written by:

Brian Clista, MD

Dr. Clista is a board-certified pediatrician who works in private practice in Pittsburgh, Pennsylvania. He previously served as a National Health Service Corporation Scholar in the inner city of Pittsburgh for 11 years.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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