Mylanta is a widely used over-the-counter medication formulated to relieve heartburn, acid indigestion, and gas. Millions of people use this liquid suspension or chewable tablet seeking quick relief from the burning sensation associated with excess stomach acid. A common concern for users is the potential for gastrointestinal side effects, particularly diarrhea. Understanding the medication’s composition and how it interacts with the body addresses this frequent question about digestive upset.
Understanding Mylanta’s Active Ingredients
Mylanta’s effectiveness stems from a combination of active compounds designed to address specific symptoms of digestive distress. Most formulations contain two primary antacids, Aluminum Hydroxide and Magnesium Hydroxide, and an anti-gas agent called Simethicone. The antacid ingredients work quickly to neutralize hydrochloric acid in the stomach, raising the stomach’s pH and alleviating the pain of heartburn.
Aluminum Hydroxide and Magnesium Hydroxide are mineral salts that react with the acid to form water and other compounds, providing rapid relief. Simethicone functions as an anti-foaming agent. It works by decreasing the surface tension of gas bubbles, allowing them to combine into larger ones that are easier to pass.
The Mechanism Behind Diarrhea
Mylanta can cause diarrhea, and this effect is directly traceable to the presence of Magnesium Hydroxide in the formulation. When taken as an antacid, a significant portion of the magnesium is not absorbed into the bloodstream from the small intestine. This unabsorbed magnesium remains in the digestive tract as it moves toward the colon.
The presence of these magnesium ions in the colon creates an osmotic effect, which causes the laxative action. Osmosis is the movement of water across a membrane to balance the concentration of solutes, such as the magnesium ions. The high concentration of unabsorbed magnesium draws water from surrounding body tissues into the intestinal lumen, significantly increasing the water content of the stool.
This increased fluid volume softens the stool. The distension of the colon stimulates peristalsis, which are the muscle contractions that move waste through the bowel. The result is a dose-dependent effect, where higher quantities of magnesium lead to softer stools and a greater likelihood of experiencing diarrhea. This effect explains why magnesium-based products are also sold separately as saline laxatives, though their inclusion in Mylanta is primarily for acid neutralization.
What to Do If You Experience This Side Effect
If Mylanta causes uncomfortable diarrhea, you can take several practical steps to manage the side effect. The first action is to reduce the dosage or frequency of the medication. Since the laxative effect is directly tied to the amount of magnesium consumed, a lower dose may provide sufficient acid relief without triggering an unwanted intestinal response.
Due to the fluid loss associated with diarrhea, increase your intake of water and other clear liquids to prevent dehydration. You can also consider switching to an antacid formulation that contains a different balance of ingredients. Aluminum-based antacids, for example, are more likely to cause constipation. Many Mylanta formulations contain both magnesium and aluminum to help balance these opposing effects.
If the diarrhea is persistent, severe, or lasts for more than a few days after stopping the medication, seek advice from a healthcare provider. Symptoms that require prompt medical attention include blood in the stool, significant abdominal pain, or signs of severe dehydration, such as excessive thirst or dizziness. Your pharmacist can also help you find suitable magnesium-free alternatives to manage your acid reflux symptoms.