Can Mylanta Cause Diarrhea? A Deep Dive into Its Side Effects

Over 60 million Americans experience heartburn at least once a month, often turning to over-the-counter antacids for relief [1.8.1]. But if you've ever wondered, Can Mylanta cause diarrhea?, the answer is yes, due to one of its key active ingredients [1.2.1, 1.3.5].

Quick Summary

Yes, Mylanta can cause diarrhea. This is a common side effect primarily attributed to its magnesium hydroxide content, which acts as an osmotic laxative.

Key Points

• Mylanta Can Cause Diarrhea: Yes, diarrhea is a common side effect of Mylanta [1.2.1].

• Magnesium is the Cause: The active ingredient magnesium hydroxide acts as an osmotic laxative, drawing water into the intestines and causing diarrhea [1.2.2, 1.4.1].

• Balancing Act: Mylanta also contains aluminum hydroxide, which causes constipation, in an attempt to balance the side effects [1.5.4].

• Side Effects Vary: Antacids with calcium carbonate (Tums) or only aluminum tend to cause constipation, not diarrhea [1.6.3, 1.8.2].

• Management is Simple: If diarrhea occurs, stay hydrated and consider switching to a magnesium-free alternative after consulting a pharmacist [1.2.1].

• Other Options Exist: For frequent heartburn, H2 blockers (like Pepcid) and Proton Pump Inhibitors (like Prilosec) are effective alternatives [1.7.4, 1.7.6].

• Consult a Doctor: If you need antacids for more than 14 days or if diarrhea is severe, it's important to see a healthcare provider [1.2.5].

What is Mylanta and How Does It Work?

Mylanta is a popular over-the-counter (OTC) medication used to relieve symptoms of excess stomach acid, such as heartburn, acid indigestion, and sour stomach [1.2.5]. Many Mylanta products are combination medications that contain two antacids—aluminum hydroxide and magnesium hydroxide—along with an anti-gas ingredient called simethicone [1.3.3]. The antacids work by neutralizing existing acid in the stomach but do not stop the production of new acid [1.5.4]. Aluminum hydroxide and magnesium hydroxide are rapid-acting, typically providing relief within minutes [1.3.3]. The simethicone component works to break up gas bubbles in the gut, alleviating bloating and discomfort [1.5.4].

The Link Between Mylanta's Ingredients and Diarrhea

The answer to the question "Can Mylanta cause diarrhea?" lies in its formulation. One of the main active ingredients, magnesium hydroxide, is known to cause diarrhea [1.2.1, 1.2.6]. In fact, magnesium-based products are often used specifically as saline or osmotic laxatives to treat constipation [1.4.1, 1.4.3]. This is why diarrhea is listed as a common side effect of taking Mylanta [1.2.1].

Interestingly, the other primary antacid ingredient, aluminum hydroxide, has the opposite effect and can cause constipation [1.2.1, 1.8.2]. Manufacturers often combine these two ingredients to try and balance these opposing gastrointestinal effects [1.5.4, 1.8.5]. However, for many individuals, the laxative effect of magnesium is more pronounced, leading to loose or watery stools [1.8.5].

Understanding the Osmotic Laxative Effect

Magnesium hydroxide causes diarrhea through a process known as an osmotic effect [1.2.2, 1.4.2]. Here’s how it works:

1. Poor Absorption: Magnesium hydroxide is poorly absorbed in the intestinal tract [1.4.2].
2. Water Retention: Because the magnesium ions remain in the colon, they draw water from surrounding tissues into the intestines through osmosis [1.4.1, 1.4.6].
3. Stool Softening: This increase in water content softens the stool and increases its volume [1.4.1].
4. Stimulated Bowel Movement: The increased volume stimulates intestinal motility, prompting a bowel movement [1.4.2].

This mechanism is effective for relieving constipation but can be an unwelcome side effect for someone simply seeking heartburn relief [1.4.3].

Not All Antacids Are Created Equal: A Comparison

The side effects of antacids depend heavily on their active ingredients. Understanding these differences can help you choose the right product.

Ingredient(s)	Common Brand(s)	Primary Side Effect	Mechanism
Magnesium Hydroxide	Mylanta, Milk of Magnesia	Diarrhea [1.2.2]	Acts as an osmotic laxative, drawing water into the bowels [1.4.1].
Aluminum Hydroxide	Amphojel, component in Mylanta	Constipation [1.2.1]	Has an astringent effect and can be constipating [1.5.4, 1.6.3].
Calcium Carbonate	Tums, Rolaids	Constipation [1.6.3, 1.8.2]	Can cause constipation, and in rare cases, kidney stones with high doses [1.6.3, 1.8.4].

Managing Diarrhea Caused by Mylanta

If you experience diarrhea while taking Mylanta, the side effect is usually mild and resolves on its own once you stop taking the medication [1.2.1]. Here are some steps you can take:

• Stay Hydrated: Drink plenty of fluids like water to prevent dehydration [1.2.1].
• Adjust Your Diet: Temporarily avoid foods that can worsen diarrhea, such as dairy products, fatty foods, or spicy foods [1.2.1].
• Consider a Lower Dose: If your symptoms are mild, reducing the amount of Mylanta you take may lessen the side effect.
• Switch Products: If the diarrhea is bothersome, stop taking Mylanta and talk to a pharmacist. They can recommend a magnesium-free antacid, such as one containing only calcium carbonate or aluminum hydroxide [1.2.1, 1.6.3].

When to Be Concerned and See a Doctor

While occasional heartburn and mild side effects from antacids are common, certain symptoms warrant a visit to a healthcare provider. You should seek medical advice if:

• You need to use antacids for more than two weeks to control your symptoms [1.2.5].
• Your diarrhea is severe, persistent, or gets worse after stopping Mylanta [1.2.1].
• You have underlying kidney problems, as your body may have difficulty clearing magnesium and aluminum, potentially leading to toxicity [1.3.5].
• You experience serious symptoms like bone pain, confusion, muscle weakness, or an irregular heartbeat [1.3.2, 1.5.6].

Alternatives for Heartburn Relief

If Mylanta isn't the right fit for you, there are other classes of medications available for heartburn:

• H2 Blockers: Medications like famotidine (Pepcid) and cimetidine (Tagamet) work by reducing the amount of acid your stomach produces [1.7.4, 1.7.6]. They take longer to work than antacids but provide longer relief [1.7.6].
• Proton Pump Inhibitors (PPIs): These are the strongest acid-reducers and include omeprazole (Prilosec), esomeprazole (Nexium), and lansoprazole (Prevacid) [1.7.4]. They block the cells that pump acid into the stomach. OTC PPIs are intended for a 14-day course of treatment [1.7.6].
• Lifestyle Changes: Simple adjustments like eating smaller meals, avoiding trigger foods, not lying down after eating, and maintaining a healthy weight can significantly reduce heartburn frequency [1.6.6, 1.7.5].

Conclusion

So, can Mylanta cause diarrhea? Yes, it is a well-documented side effect caused by its magnesium hydroxide content, which has a laxative effect [1.2.2, 1.3.5]. This is often balanced by aluminum hydroxide, which can cause constipation, but the diarrheal effect can still prevail [1.5.4]. If you experience this side effect, managing hydration is key, and numerous alternatives, from different types of antacids to H2 blockers and PPIs, are available [1.2.1, 1.7.4]. For persistent symptoms of either heartburn or diarrhea, consulting a healthcare provider is the best course of action to ensure proper diagnosis and treatment [1.2.5].

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For more information from a trusted source, you can visit MedlinePlus for details on antacids.

Frequently Asked Questions

Why does Mylanta cause diarrhea?

Mylanta causes diarrhea because it contains magnesium hydroxide, which is an osmotic laxative. It works by drawing more water into your intestines, which softens stool and can lead to diarrhea [1.4.1, 1.4.2].

Is diarrhea from Mylanta a common side effect?

Yes, diarrhea is considered a common side effect of any antacid containing magnesium [1.2.1, 1.2.5]. However, many people may not experience it or may have only mild symptoms.

What should I do if I get diarrhea after taking Mylanta?

If you experience mild diarrhea, ensure you drink plenty of fluids to avoid dehydration. The symptom usually goes away when you stop taking the medication. If it's bothersome, talk to a pharmacist about a magnesium-free alternative [1.2.1].

Do all antacids cause diarrhea?

No. Antacids containing aluminum hydroxide or calcium carbonate (like Tums) are more likely to cause constipation [1.6.3, 1.8.2]. Diarrhea is primarily associated with magnesium-containing antacids [1.2.2].

How long does diarrhea from Mylanta last?

Diarrhea from Mylanta is usually temporary and should resolve on its own after you stop taking the product [1.2.1]. If it persists for more than a couple of days after stopping, you should contact a healthcare provider.

Can I take something to stop the diarrhea from Mylanta?

It is generally better to stop taking the Mylanta to see if that resolves the issue [1.2.1]. If diarrhea is severe, consult your doctor or pharmacist before taking an anti-diarrheal medication.

Are there alternatives to Mylanta that won't cause diarrhea?

Yes. You can try antacids based on calcium carbonate (like Tums) or other classes of medication like H2 blockers (e.g., Pepcid) and Proton Pump Inhibitors (e.g., Prilosec), which are less likely to cause diarrhea [1.7.4, 1.7.5].