An update on IBS treatment — What actually works?

Ashleigh Jones
Consulting Dietitian

Irritable bowel syndrome (IBS) affects around 1 in 5 Australians.¹

It is considered to be a functional gastrointestinal disorder, meaning that patients report symptoms despite a lack of chemical, radiological or physiological abnormalities.²

The main symptoms of IBS are:

• abdominal pain or discomfort that is usually relieved by passing wind or a bowel movement
• abdominal bloating/distention
• chronic diarrhoea or constipation, or alternating between the two.

There is no known cause or cure for IBS. It cannot be confirmed by blood tests or radiological examinations and is therefore effectively a diagnosis by exclusion.

It’s essential that patients with the above symptoms are examined by their GP in the first instance as these symptoms can indicate more serious conditions such as coeliac disease, inflammatory bowel disease and some cancers.

There are a number of factors that can trigger the symptoms of IBS in susceptible individuals:

1. Infection: a severe bout of gastroenteritis may result in persistent IBS symptoms in some individuals.
2. Food intolerance: individuals with lactose intolerance may experience bloating, cramping and diarrhoea after consuming foods that are rich in lactose. This can be managed with the use of lactose-free dairy products, or the addition of Lacteeze or Lactaid products which assist with digestion of lactose.
3. Stress: for susceptible individuals, acute stress and strong emotions (both positive and negative) can trigger symptoms.
4. Medications: certain antibiotics, antacids and painkillers.

Once other conditions have been ruled out and a diagnosis of IBS has been made, there are a number of strategies that can be used to manage the symptoms of IBS.

As there is no known cure for IBS, management strategies are aimed at symptomatic relief. These strategies are as follows.

Exclusion of common dietary triggers

Fatty foods, spicy foods, alcohol, caffeine and coffee (even decaffeinated coffee) may exacerbate IBS symptoms in susceptible individuals.

These foods should be reduced, if not eliminated, on a trial basis to assess whether they play a role in a person’s IBS symptoms.

After a period of elimination, they can then be reintroduced gradually to determine individual tolerance.

Low FODMAP diet

The low FODMAP diet is effective in managing symptoms in up to 70% of individuals with IBS.³

This diet reduces the intake of various fermentable carbohydrates known collectively as ‘FODMAPs’.

FODMAPs are found in a range of nutritious foods such as onions, garlic, cauliflower, legumes and wheat. They are also found in food additives such as inulin, xylitol and isomalt.

In diet-responders, reduced dietary intake of FODMAPs results in a reduction in gas production in the large intestine and an improvement in IBS symptoms.

This diet is restrictive and excludes various foods that are important for gut health and overall wellbeing.

It has been shown that the low FODMAP diet reduces the variety and number of beneficial bacteria in the gut.⁴

For this reason it should only be followed in the short term, under the guidance of an Accredited Practising Dietitian with experience in IBS and food intolerance.

The low FODMAP diet is used as a tool to identify an individual’s triggers for IBS symptoms.

It is followed for approximately 2–8 weeks, at which time eliminated foods are gradually reintroduced to the diet in a strategic manner.

Once all eliminated foods have been re-trialled, the patient commences a modified low FODMAP diet which maximises dietary variety and excludes only their known triggers.

Soluble fibre

While many people associate dietary fibre with constipation treatment, soluble fibre is beneficial for individuals with both constipation- and diarrhoea-predominant IBS.

It can help to soften stools in individuals with constipation, while helping to add bulk by drawing water from the stool of those with diarrhoea.

Soluble fibre is found in a variety of foods including fruits, vegetables, oats and barley.

Note that in constipation-dominant IBS it is particularly important to increase fluid intake along with fibre intake to avoid worsening the issue.

With regards to dietary supplements, psyllium husk is derived from the seeds of the Plantago ovata plant. It is rich in soluble fibre, inexpensive and is well tolerated by individuals with IBS.

Commercial soluble fibre supplements such as Metamucil and Pronourish Natural Balance Fibre may be more palatable and easy to use, especially Benefiber which is tasteless and odourless, and virtually undetectable in foods and drinks.

Iberogast

Iberogast is a herbal remedy that is reported to improve a range of symptoms including stomach pain, abdominal cramps, bloating, gas and nausea.

The effectiveness of Iberogast has been investigated in six double blind, randomised, controlled trials, showing significantly greater symptomatic relief than a placebo.⁵

It can be used while undertaking a low FODMAP diet; however, it will need to be excluded if a patient is undertaking a low chemical diet.

Probiotics

While there is emerging evidence that probiotics may be useful in managing the symptoms of IBS, the research is in its infancy and we cannot yet say with certainty which strains, if any, will work for which individuals.⁶

Some individuals have reported bloating and worsening symptoms with probiotic use.

If a patient wishes to trial a probiotic, the decision of which probiotic to take will come down to individual trial and error, as individuals will tolerate some strains better than others.

We do not yet have the ability to predict an individual’s response to a probiotic.

Conclusion

IBS is a complex condition that is best managed with the assistance of a GP and an Accredited Practising Dietitian with experience in IBS and food intolerance.

Patients may find that fibre supplements such as Metamucil, Pronourish Natural Balance Fibre and Benefiber improve symptoms of constipation and diarrhoea, while Iberogast can also be useful.

While some patients may choose to consume probiotics, tolerance does vary.

References

1. https://www.gesa.org.au/resources/patients/irritable-bowel-syndrome/
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5704116/pdf/jcm-06-00099.pdf
3. https://www.ncbi.nlm.nih.gov/pubmed/28244668
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390324/
5. https://hcp.iberogast.com.au/
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4907258/