Episode 121 – Supplements For IBS

Key Topics Covered

IBS cartoon.

  • This will cover all forms of IBS including constipation-specific, diarrhoea-specific, and mixed.
  • Other episodes talking about IBS include Episode 7 which was on FODMAPs and IBS and Episode 9 which was “What To Do If FODMAPs Doesn’t Work”.

Metamucil / Psyllium Husk 

Psyllium husk & metamucil supplements.
  • Helps with both IBS-C and IBS-D.
  • Psyllium husk is a form of soluble fibre.  
  • It is specifically well known for helping with constipation. It absorbs water and makes a gel-like substance that makes the stool easier to pass. 
  • 10g of psyllium husk per day often improves all symptoms of constipation by ~50% on average.  
  • Addressing constipation helps with gas and bloating too. 
  • A lesser-known benefit of psyllium husk is that it can help mild-moderate diarrhoea by helping to absorb or soak up, some of the water 

Peppermint Oil 

Peppermint Oil

  • Peppermint oil contains menthol which can help the intestines relax and allow trapped gas to pass through
  • Allowing the trapped gas to pass through is the predominant feature that helps bloating. 
  • The relaxation of the intestinal muscles can also reduce nerve-related pain if relevant on an individual basis.   
  • From a stool perspective, since trapped gas can compact fecal matter, it may also help with constipation issues  


  • The most extensive review of peppermint oil included data from over 800 patients from twelve clinical trials.
    • The review showed IBS symptoms were 44% less common in patients who took the peppermint oil group compared to those who took a placebo. 


  • For adults, a dosage of 0.2ml to 0.4ml of peppermint oil 3 times a day taken in the form of coated capsules works best e.g. MINTEC.
    • Peppermint tea is not as effective.
    • A common side effect is reflux.



  • Different types of bacteria are helpful for different conditions. The most common and well-researched are species of Lactobacilli and Bifidobacteria
  • Those with IBS on average have lower amounts of both of those. 


  • Research is mixed on the effectiveness
  • A 2022 review summarising the research highlighted that on average, they provide benefits. 
  • An earlier one from the British Dietetic Association had a key finding that summarised the research well:
    • Of the 29 studies they assessed, 14 of them showed a positive result. That means that just under 50% had a benefit. 
    • Exploring the specific strains that are most linked with the benefits would be a whole podcast in itself. There are some relevant blog posts on this are in the list below.

Digestive Enzymes 

Intoleran digestive enzyme products.
  • This area can be confusing as there are a lot of people marketing these unnecessarily and without context. But there are specific ones that could be helpful
  • Lactase for lactose intolerance e.g. ‘Lacteeze’.
  • Sucrase for CSID (sucrase-isomaltase insufficiency) e.g. ‘Sucraid’ & ‘Starchaway’.
  • Creons (requires a prescription) for conditions where the pancreas cannot produce enough enzymes.
  • Other FODMAP enzymes e.g. ‘Intoleran’ is a company that sells these.
  • In most cases, you will want to figure out your issue first and then supplement it with the appropriate enzymes.
    • Although technically these enzymes can also be used as tools to help identify this. 

Honourable Mentions

The areas listed above are the main ones, however, there are others that are worth mentioning.


Iberogast Supplement.
  • This is made up of 9 different plant extracts – including sources like peppermint, licorice, and chamomile.
  • There are quite a few studies on this product, with positive findings for all symptoms of IBS AND reflux.
    • These studies were all funded by the company. This is not a huge deal, but something to consider.
      • Dosage is 3x per day before meals.


  • This helps reduce symptoms of gas/bloating by helping to break up gas bubbles in the gut.  
  • Personally, this is not something we use much with clients.


L-GLutamine Supplement.
  • Glutamine is the most abundant amino acid in the body 
  • Theoretically, it can help support the gut wall, reduce intestinal permeability, and help improve the gut microbiome.
  • Some research has found it helps.
  • Overall, there is not a significant amount. of research on this, which is why it is in the honorable mentions section. 

Magnesium Citrate 

Magnesium Citrate Supplement.

  • 300mg+ of magnesium citrate is often used as a laxative and can help with constipation.

Vitamin D

Vitamin D3

  • There is clear data showing that people with IBS, on average have lower levels of vitamin D.
  • That by itself isn’t a strong enough link though.
  • Ideally, we need a large body of research showing people who were previously deficient having improved symptoms by addressing the deficiency.
  • As of my last time checking (2022), there were 4 studies looking at that and 3 out of the 4 found benefits to increasing vitamin D levels. 

Relevant Links / Resources

Blog Posts

Studies Mentioned

Useful Website