Magnesium for IBS Constipation: Everything You Need to Know

Can something as simple as magnesium for IBS constipation help alleviate this uncomfortable condition? 

The short answer is yes; magnesium has a laxative effect.  

But let’s dig in some more to find out how magnesium helps alleviate constipation for people with IBS, food sources of magnesium, and how to use magnesium supplements.

Which IBS symptoms are helped by magnesium?

Not all irritable bowel (IBS) is the same, so magnesium will also affect types of IBS differently too.  

  • IBS constipationpredominant symptoms are as you would expect:  having bowel movements that are slow to pass, difficult to pass, and infrequent bowel movements. This type of IBSis most benefited by magnesium supplementation. 
  • IBS diarrheapredominant symptoms present mostly with diarrhea but also can occasionally have constipation. Magnesium supplements should be mostly avoided with this type of IBS. 
  • IBS-mixed can have alternating symptoms from diarrhea to constipation. Magnesium benefits this condition, but should be used in smaller doses and stopped if diarrhea occurs. 

The type of IBS that is helped most by magnesium is IBS constipation. 

Many people struggle with IBS and abdominal pain related to it their whole lives, thinking it is their “normal.” But did you know that chronic constipation is actually linked to an increased risk of heart disease mortality [R]? 

So, the pesky IBS symptoms you are having should be taken seriously and prevented by diet when possible.  

Interesting facts about magnesium

Over 600 enzyme reactions in the body require magnesium to perform normally [R].  And, almost 4000 types of protein in the body bind with magnesium [R].

Getting magnesium from your diet

You should aim to get more magnesium-rich foods in your diet if you have IBS.  

Try to regularly eat these magnesium foods [R]: 

  • Leafy greens: spinach, kale, asparagus, parsley, arugula, swiss chard
  • Nuts and Seeds: shelled pumpkin seeds, almonds, cashews, Brazil nuts, chia seeds, peanuts
  • Meats and fish: caviar, cod, wild-caught salmon, mackerel
  • Legumes and grains: black beans, lentils, chickpeas, quinoa *soak and sprout these foods, pressure cook when possible to reduce phytic acid. Tempeh is fermented so its bioavailability is better
  • Other: chlorella, spirulina, water lentils, molasses
  • Fruits: avocado, figs, bananas 

Unfortunately, there has been an ongoing decline of magnesium in soils and bioavailability of magnesium from foods [R].  While this is a difficult situation to quantify, it makes it all the more important that magnesium deficiency is addressed for people with IBS constipation. 

Grains, legumes, and nuts are good sources of magnesium, but much of it is bound up in phytate making it difficult to absorb.  That’s why I recommend getting most of your magnesium from greens, seafood, and fruits. 

Try to sprout grains and legumes when possible to increase the availability of magnesium. I generally don’t recommend wheat and rye products because they can increase leaky gut syndrome [R]. 

Best magnesium for IBS

The best magnesium supplement for IBS is going to be one that helps both constipation and other symptoms you may be having.  

If you have IBS constipation (IBS-C), you can make a choice of magnesium type based on these symptoms. As always, check with your healthcare provider before starting any new supplements.

Conditions with IBS-CBest type of magnesium
IBS-C alonemagnesium oxide, magnesium hydroxide, magnesium sulfate, magnesium citrate [R, R]
IBS-C + sleep issuesmagnesium oxide, magnesium hydroxide [R]
IBS-C with fibromyalgia/migrainesmagnesium oxide, magnesium malate [R]
IBS-C with memory issuesmagnesium threonate, magnesium sulfate [R, R]
IBS-C with mood issuesmagnesium chloride, magnesium carbonate [R]
IBS-C with high blood pressuremagnesium chloride [R]
IBS-C with diabetesmagnesium chloride [R]
IBS-C with indigestionmagnesium carbonate, magnesium oxide [R]

How does magnesium for IBS work?

Magnesium benefits the gut and may reduce constipation in many ways: by softening the stool, relaxing the intestines, helping reduce inflammation, enhancing probiotic effects, and may reduce intestinal permeability (leaky gut). 

Adequate magnesium levels may even reduce your risk of getting digestive cancers. 

Let’s take a closer look. 

Magnesium softens the stool

As an osmotic laxative, magnesium works by increasing the amount of fluid in the digestive tract.  This means that magnesium helps to soften the stool, making it easier to pass [R]. 

This is a good feature of a laxative because it means that magnesium is not habit-forming. In other words, people don’t become dependent on magnesium like other laxatives.  

Magnesium for constipation

Using magnesium for constipation is very commonplace in healthcare.  It is even used in bowel preps prior to colonoscopies.

In Japan alone, over 10 million people annually use magnesium oxide for constipation, indicating its relative safety and effectiveness [R]. 

But, does magnesium for IBS constipation work according to research? 

Two studies show that it does.  

A research study published in the Journal of Neurogastroenterology and Motility explored how magnesium works for chronic constipation.  34 women with mild-to-moderate chronic constipation were given magnesium oxide at 500 mg daily.  

This treatment increased spontaneous bowel movements and reduced intestinal transit time as well as improved quality of life as compared to placebo  [R]. 

Magnesium oxide worked as well as senna for chronic constipation in a recent study published in the American Journal of Gastroenterology [R]. Both treatments improved the frequency of bowel movements and improved quality of life compared to placebo. 

Related post: Milk Thistle for IBS, Liver Health, and More | The Healthy RD

Relaxes the intestines

Magnesium may alleviate constipation by relaxing the smooth muscles of the intestinal wall.  This helps ease bowel movements. 

While more research is needed, people who take magnesium supplements use less straining while “going.”  This suggests that magnesium helps overall with muscle relaxation [R]. 

Magnesium may reduce inflammation

Inflammation is related to IBS constipation and so is magnesium deficiency [R].  In fact, people with IBS constipation have much higher levels of an inflammatory marker called c-reactive protein than healthy people [R]. 

Does taking magnesium help dampen inflammation in the body? 

Early research suggests that it does.  

Magnesium deficiency caused inflammation by increasing intestinal “leak” in a rat study [R]. Lack of magnesium also increases major inflammatory compounds called NFkB and glutathione [R]. 

May enhance gut bacteria

When your diet is low in magnesium, you are more likely to have altered gut bacteria, which spells trouble for constipation [R]. 

In fact, mice who were deficient in magnesium had lower levels of beneficial bacteria called Bifidobacterium [R].

A mineral-rich supplement including magnesium enhanced the microbiome in rats, although more research is needed to see if it works in humans [R].  

Magnesium leaky gut connections

A number of studies indicate that low levels of magnesium can impair the gut lining or can cause a leaky gut.   

According to Medical News Today, leaky gut is linked to chronic constipation and IBS as well as inflammatory bowel diseases. 

If you are low in magnesium, the intestinal wall may lose its normal function of protecting you [R]. 

Early research shows that using magnesium helps to keep the cells of the intestines from leaking by improving intestinal cell growth, survival, and integrity [R]. 

What does this all mean for you?  Magnesium likely helps protect your gut lining, which in turn may help ease IBS constipation. 

May reduce cancer risk

Low intake of magnesium is linked to an increased risk of pancreatic cancer.  In fact, for every 100 mg below the recommended intake of magnesium a person gets, there is an incremental 24 percent increase in the risk of pancreatic cancer [R]. 

Higher magnesium intake is also related to a reduced risk of colon cancer [R].

Magnesium deficiency symptoms

Magnesium deficiency is likely contributing to most health conditions today. 

Lack of magnesium creates vague, nagging symptoms, making it go undetected for prolonged periods.

These vague magnesium deficiency symptoms may be the “tip of the iceberg” in the body.

Magnesium deficiency may show up as:

  • Muscle cramps
  • Headaches
  • Migraines
  • Nervousness
  • Digestive distress
  • Constipation
  • Insomnia
  • Fatigue
  • Aches and pains

Unfortunately, blood magnesium tests don’t often detect magnesium deficiency. This is because magnesium is primarily stored in the bone. See the graph below to find out where your body stores magnesium.

Pie chart of body distribution of magnesium: 53 percent bone, 0.8 percent blood, muscle 27.1%, Soft tissue 19% by The Healthy RD
Source Swaminathan R Magnesium metabolism and its disorders <em>The Clinical biochemist Reviews<em> vol 242 2003 47 66

The only way to know if you are magnesium deficient for sure is to review your dietary intake and risk for deficiency with a qualified registered dietitian or functional medicine provider who has adequate training in magnesium assessment.

Many people don’t eat enough magnesium

About 60 percent of Americans don’t even meet the RDI for magnesium intake [R, R].

The table below represents the average daily recommended intake of magnesium by age, gender, pregnancy, and lactation.

14-18410 mg360 mg400 mg360 mg
19-30400 mg310 mg350 mg310 mg
31-50420 mg310 mg350 mg320 mg
51+420 mg320 mg

Since most people don’t make this recommendation, supplementation can be a feasible option for many people.

And, some conditions increase requirements for magnesium. Keep in mind, the RDI is set for healthy people, not for people suffering from health issues.

Other reasons you may need magnesium

By now you know that magnesium is critical for constipation, and just about every function in the body.

This next section reviews the specific areas do we know that magnesium may help you.

Magnesium benefits sleep and metabolism

Every ounce of energy produced in your body requires magnesium to catalyze or stimulate energy production.

Magnesium is also important for maintaining the mitochondria, or energy-producing part of the cell as well.

This energy helps your heart to pump, all of your muscles to contract, and to help you sleep well. 

Your energy depends on your ability to sleep well, too, and adequate magnesium helps facilitate high-quality sleep [R].

Magnesium for diabetes

Magnesium is involved in over 600 reactions in the body, and of those that may be of interest to many is that it helps regulate insulin production [R].

It also helps cells take in glucose for energy.

The uptake of glucose into your cells is yet another way that magnesium helps with energy.

Unfortunately, diabetes creates a situation where people actually lose more magnesium than people who don’t have it and they are the ones that might benefit the most from it [R].

Lack of magnesium in the diet may make it more likely to get diabetes as well[R]. Although not proven to be causal yet, per each increase in 100 mg of magnesium intake, there may be an 8-13% reduction in diabetes risk [R].

Magnesium for muscle benefits

Magnesium may help muscle strength by normalizing or balancing testosterone levels, both in sedentary and athletes [R].

Magnesium helps the muscle by providing the muscle tissue with energy.

The gain of muscle tends to occur at intake levels of between 250 mg and 500 mg of magnesium per day.

Athletes exerting strenuous activity also lose more magnesium, compounding the effects of muscle fatigue.

Magnesium is anti-aging

Premature aging is related to DNA damage in our cells. Magnesium helps to prevent premature aging by reducing “breaks” in your DNA due to oxidative stress [R]

This is important because DNA gene breaks are related to aging and also increase the risk for cancer.

Magnesium also helps to stabilize DNA and reduces aging-related processes within cells [R].

Low intake of magnesium might shorten the protective part of the chromosomes called telomeres and may stimulate the production of aging genes (senescence genes) [R].

Magnesium helps normal brain function 

Magnesium may be critical for preventing age-related memory loss [R]

In mice, low levels of brain magnesium directly correlate to poor memory function [R].

Further, magnesium-supplemented older rats showed significantly better memory and recall than young rats who didn’t get magnesium [R]. Magnesium helped improve long-term memory in this study.

Some researchers even propose that the development of Alzheimer’s disease may even be reversed following magnesium therapy [R].

In a recent study, rats were supplemented with magnesium over a 17-month period, and this reduced harmful amyloid plaque accumulation over those who did not receive magnesium.

A well-known brain benefit of magnesium is that it helps with mood, anxiety, and stress too [R].

Some evidence even suggests that magnesium may even help with attention deficit disorders [R].

While it’s too soon to say that magnesium has all of these brain benefits in humans, the results show promise for the benefits of magnesium.

Magnesium heart benefits

Magnesium has numerous cardiovascular benefits that stand the test of time. A few of those benefits are listed here:

  1. Heart patients performed better on exercise tests after supplemental magnesium [R]
  2. Magnesium is also used routinely to help with heart rhythm issues by cardiologists [R]
  3. People who eat magnesium-rich diets may reduce chances of heart disease [R]
  4. It reduces the chance of sudden cardiac death in men and women [R, R]

Magnesium supplementation safety

Supplementation for most people is safe, but make sure you check with your healthcare provider if you decide you want to take magnesium.

Certain medications like antibiotics and bisphosphonates need to be taken at separate times in the day from mineral supplements like magnesium.

Keep in mind that blood tests of magnesium are usually not an accurate representation of magnesium status, as magnesium is stored inside of cells, not in the blood.

Common side effects of magnesium supplementation include diarrhea and nausea [R, R].

Magnesium supplementation tips

More is not necessarily better when it comes to supplemental magnesium. Generally speaking, follow the package directions when taking a magnesium supplement.  

You can start with a smaller dose to improve tolerance to magnesium.  It is wise to start with a low dose, around 100-200 mg per day of magnesium. Then, work your way up to the desired dose as tolerated.

To make magnesium with food to prevent side effects.

It is always smart to focus on eating magnesium from food first whenever possible.

Magnesium-rich foods have so many other health benefits: they have anti-cancer properties, are high in fiber, act as a prebiotic, and more.

Related post: Pumpkin for Constipation: Its Gentle and Evidence-Based Benefits

Drugs that deplete magnesium

In addition to the conditions like diabetes, many drugs and food may deplete magnesium and include:

  • Diuretics
  • Acid Blockers
  • Antacids
  • Antibiotics
  • Corticosteroids
  • Antiviral medications
  • ACE inhibitors
  • Breast cancer drugs
  • Stimulants like Ritalin
  • Alcohol
  • Sugar

If you consume any of these types of medications or foods on a regular basis, make sure to get adequate magnesium in your diet.


Minerals like magnesium are dynamic and powerful factors that can make the difference between sickness and health. Magnesium health benefits are seemingly endless with over 600 known functions in the body.

By adding more magnesium-rich foods and supplementing high-quality supplements, you may have less IBS, feel better, and sleep better.

As with anything, check with your doctor before adding any new supplements into your routine.

1 thought on “Magnesium for IBS Constipation: Everything You Need to Know”

  1. Lots of great information here. Worth trying. Have had IBS-C for 50 years – on and off, believe definite relation to stress

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