Can Magnesium Relieve Constipation?

Constipation is a common digestive condition characterized by hard, lumpy, and dry stools that are difficult or painful to pass. A person is generally considered constipated if they have three or fewer weekly bowel movements. 

Constipation is one of the most common digestive disorders in the United States, with 16 out of 100 adults having symptoms of constipation each year. The condition is typically caused by a lack of dietary fiber, inadequate water intake, a sedentary lifestyle, certain medications, or underlying medical conditions.

While lifestyle changes are often recommended to relieve constipation, magnesium is a well-known remedy. Certain types of magnesium can soften stools and stimulate bowel movements, providing short-term relief of constipation.

Best Types of Magnesium for Constipation

While several forms of magnesium are available over-the-counter (OTC), only some relieve constipation. These include:

• Magnesium citrate: Magnesium citrate is one of the most easily absorbed forms of magnesium. Its high solubility and rapid absorption make it a highly effective laxative, commonly used to treat occasional constipation and to empty the colon before a colonoscopy.
  
• Magnesium oxide: Although not as readily absorbed as magnesium citrate, magnesium oxide has been well-studied for treating constipation. This form of magnesium helps improve the regularity of bowel movements, soften the consistency of stools, and alleviate stomach discomfort.
  
• Magnesium hydroxide: Often referred to as Milk of Magnesia, this is the liquid form of magnesium oxide. It is used for short-term relief of constipation and to reduce symptoms of heartburn, indigestion, and upset stomach. 
  
• Magnesium sulfate: Commonly known as Epsom salt, magnesium sulfate can treat constipation when dissolved in water and consumed. Researchers have found that natural mineral water containing magnesium sulfate helps improve stool consistency and bowel frequency.

How Magnesium Helps Relieve Constipation

The types of magnesium mentioned above help relieve constipation by acting as osmotic laxatives. Osmotic laxatives draw water from surrounding tissues into the intestinal lumen, the hollow space inside the intestines. This inflow of water helps soften stools, making them easier to pass.

With more water in the intestinal lumen, the intestinal walls begin to expand, a process known as luminal distention. This stretching effect triggers the colon muscles to contract and relax rhythmically, a motion known as peristalsis. These wave-like movements help move stool through the intestines.

These events promote the process of laxation, facilitating the smooth and comfortable passage of stool from the body. Osmotic agents like magnesium rely on the movement of water rather than direct stimulation of intestinal muscles like some other laxatives, making magnesium a gentle and effective constipation treatment.

How To Take Magnesium for Constipation

Magnesium is available in powder, pill, or liquid form and usually stimulates bowel movements within 30 minutes to six hours after ingestion. Avoid taking magnesium laxatives long-term to prevent dependency.

The appropriate dosage varies depending on the specific type of magnesium used:

• Magnesium citrate (liquid): Adults and children over 12 should take 6.5-10 fluid ounces daily. Children 6-12 years take a smaller dose of 3-7 fluid ounces daily. Children 2-6 should only take 2-3 fluid ounces daily. 
• Magnesium oxide (pill): Magnesium oxide typically comes in pill form; take it with 8 ounces of water to encourage bowel movements. Take 1-2 tablets a day or as directed by your healthcare provider.
• Magnesium hydroxide (liquid): Adults and children over 12 should take 30-60 milliliters of magnesium hydroxide in a 24-hour period. Children 6-11 years should take 15-30 milliliters. 
• Magnesium sulfate (dissolved in water): Adults and children over 12 should consume 2-4 teaspoons of magnesium sulfate dissolved in 8 ounces of water. Children 6-11 should drink 1-2 teaspoons using the same preparation. 

Food Sources of Magnesium

To promote bowel regularity, you may also consider increasing your intake of magnesium-rich foods such as:

• Pumpkin seeds (1 ounce (oz)): 156 milligrams (mg) of magnesium
• Chia seeds (1 oz): 111 mg
• Almonds (1 oz): 80 mg
• Boiled spinach (1/2 cup): 78 mg
• Cashews (1 oz): 74 mg
• Soy milk (1 cup): 61 mg
• Black beans (½ cup): 60 mg
  

Potential Side Effects and Precautions

Although magnesium is a gentle and effective way to relieve constipation, there are several side effects and precautions to be aware of.

It's crucial to take your magnesium as directed and follow the instructions on the product label to avoid exceeding the recommended dosage and duration. High doses of magnesium are associated with unpleasant symptoms, including: 

• Abdominal pain
• Cramping
• Diarrhea

Extremely high doses of magnesium laxatives can lead to magnesium toxicity, which may present with symptoms such as:

• Nausea
• Vomiting
• Facial flushing
• Urine retention (difficulty emptying the bladder)
• Muscle weakness
• Difficulty breathing
• Low blood pressure
• Irregular heartbeat

People with kidney disease should avoid magnesium-containing laxatives, as they can cause elevated magnesium blood levels, resulting in serious complications such as complete heart block and cardiac arrest.

Magnesium may negatively interact with certain medications, such as bisphosphonates, antibiotics, diuretics, and proton pump inhibitors. Experts recommend taking these medications at least two hours before using magnesium.

For individuals who are pregnant or breastfeeding, consult your healthcare provider before taking any new supplements.

Other Tips for Preventing and Treating Constipation

Magnesium laxatives aren't the only treatment option for constipation.

The first-line recommendations for preventing and treating constipation are dietary and lifestyle changes, which include:

• Regular physical activity: Exercise helps improve colonic transit time (the amount of time it takes for food to move through the colon) and increases the number and weight of stools.
• Increasing dietary fiber intake: Dietary fiber in fruits, vegetables, nuts, seeds, and whole grains helps bulk up and soften stools. Gradually increase your fiber intake to 20-35 grams per day.
• Drinking enough water: Aim to drink 1.5-2 liters of water daily.
• Limit high-fat, processed foods: High-fat meats, dairy, processed foods, and sweets can contribute to constipation.

When To See a Healthcare Provider

If you've tried regular exercise, increasing fiber, drinking more water, and using magnesium laxatives to treat your constipation with no success, consider reaching out to your healthcare provider.

You should also seek medical care if you experience constipation with any of the following symptoms:

• Blood in your stool
• Severe abdominal pain
• Unintended weight loss
• Rash or hives
• Itching
• Dizziness
• Mental or mood changes
• Weakness
• Nausea
• Vomiting

These symptoms may indicate a more serious underlying condition, particularly when they last longer than three weeks. Seeking medical advice can help ensure proper diagnosis and treatment.

A Quick Review

Constipation is characterized by hard, uncomfortable bowel movements that occur less than three times a week. Dietary changes, hydration, and regular exercise are the first steps to treating constipation.

Magnesium offers a gentle and effective solution to relieve discomfort and support regularity when additional treatment is needed. The types proven to help with constipation include magnesium citrate, magnesium oxide, magnesium hydroxide, and magnesium sulfate.

These forms of magnesium draw water into the intestines, helping soften stools. High doses or prolonged use of magnesium laxatives can cause side effects. Consult a healthcare provider for guidance for your individualized needs.