IBS & Low FODMAP Diet: Everything You Need to Know

Reviewed with reference to Monash University guidelines and developed by the Froyda nutrition team.

Irritable Bowel Syndrome (IBS) is one of the most common functional gut disorders worldwide, affecting around 10–15% of the population. It is characterised by symptoms such as abdominal pain, bloating, gas, diarrhoea, constipation, or a combination of both. For many people, these symptoms are closely linked to food intake.

Although IBS does not cause structural damage to the digestive system, it can significantly impact daily comfort, wellbeing, and quality of life.

One of the most researched and effective dietary approaches for managing IBS symptoms is the low FODMAP diet, developed by researchers at Monash University.

In this article, we’ll explain what IBS is, how FODMAPs affect digestion, and how a low FODMAP approach can help improve gut comfort.

What is IBS or Irritable Bowel Syndrome?

IBS (Irritable Bowel Syndrome) is a chronic gut–brain interaction disorder. This means the digestive system is structurally normal but reacts more sensitively to certain triggers.

IBS affects an estimated 5–10% of people worldwide, making it one of the most common gastrointestinal disorders globally.

IBS can cause symptoms such as abdominal pain, bloating, excess gas, diarrhoea, constipation, or a combination of both. Symptoms can vary considerably from person to person and often fluctuate over time.

Although IBS does not increase the risk of more serious conditions such as inflammatory bowel disease or bowel cancer, it can have a significant impact on quality of life, making everyday activities, social occasions, and food choices more challenging for those affected.

Common IBS symptoms

• Abdominal pain or cramping
• Bloating and visible distension
• Excess gas
• Diarrhoea, constipation, or alternating bowel patterns

IBS Triggers

While the exact cause is not fully understood, IBS symptoms are often influenced by:

• Certain carbohydrates in food (FODMAPs)
• Stress and emotional factors
• Gut sensitivity and motility changes
• Lifestyle factors such as sleep and eating patterns

What Are FODMAPs? Understanding IBS Food Triggers

FODMAPs are a group of short-chain carbohydrates that are poorly absorbed in the small intestine. The term stands for:

• Fermentable
• Oligosaccharides
• Disaccharides
• Monosaccharides
• And
• Polyols

These compounds can be found in a wide variety of everyday foods, including wheat, onions, garlic, apples, dairy products, and certain sweeteners

When FODMAPs reach the large intestine, they can draw water into the gut and are fermented by gut bacteria. This fermentation process produces gas, which can contribute to symptoms such as bloating, abdominal pain, and changes in bowel habits in people with IBS.

The Monash University Approach to the Low FODMAP Diet

The Monash University Low FODMAP Diet™ is a structured, evidence-based approach designed to help people with medically diagnosed IBS identify their personal food triggers while improving digestive comfort.

Studies show that approximately 70–75% of people with IBS experience symptom improvement when following a structured low FODMAP approach.

Importantly, the Monash University Low FODMAP Diet™ is not a permanent elimination diet. According to Monash University, the goal is to reduce symptoms, systematically test tolerance, and then create the least restrictive long-term diet possible. This helps protect nutritional balance, gut microbiome diversity, and overall quality of life.

The 3 phases of the low FODMAP diet

Phase 1: Low FODMAP Diet (Elimination)

The first stage involves temporarily reducing high FODMAP foods for approximately 2–6 weeks under professional guidance.

The goal:

• Calm IBS symptoms
• Determine whether FODMAPs are contributing to digestive issues
• Create a stable baseline before testing individual triggers

How it works: Rather than simply removing foods, this phase focuses on substituting high FODMAP foods with low FODMAP alternatives. For example:

• Wheat bread → sourdough spelt or low FODMAP alternatives
• Onion → chives or garlic-infused oil
• Apples → oranges or berries

Monash emphasises that this stage should not be followed longer than necessary, as unnecessary long-term restriction can negatively impact dietary variety and beneficial gut bacteria. If symptoms do not improve during this phase, IBS symptoms may not primarily be driven by FODMAPs, and other treatment approaches may need to be explored.

Phase 2: Reintroduction Diet (Challenge Phase)

Once symptoms improve, the second stage begins: systematic reintroduction. Different FODMAP groups are systematically reintroduced to identify personal triggers.

The goal:

• Identify which specific FODMAP groups trigger symptoms
• Determine tolerated serving sizes
• Expand the diet as much as possible

How it works: During this phase, each FODMAP subgroup – such as fructose, lactose, fructans, GOS, sorbitol, or mannitol – is systematically tested one at a time while the rest of the diet remains low FODMAP. This process involves gradually increasing the serving size of each challenge food over several days, carefully monitoring symptoms throughout, and allowing washout periods between each reintroduction to accurately identify personal triggers and tolerance levels.

A washout period is a short break between testing different FODMAP groups during the reintroduction phase of the low FODMAP diet.

The reintroduction phase usually takes around 6–8 weeks, depending on individual tolerance and response.

Monash strongly recommends working with a dietitian during this process, as proper reintroduction is essential for accurately identifying triggers while avoiding unnecessary long-term food restriction.

Phase 3: Personalisation Diet (Maintenance)

The final stage is where the diet becomes sustainable. A long-term, flexible diet is created based on individual tolerance.

The goal:

• Build a long-term eating pattern based on personal tolerance
• Reintroduce as many foods as possible
• Restrict only foods that reliably trigger symptoms

After identifying individual sensitivities, tolerated foods are gradually reintroduced into regular eating patterns, while only those that consistently trigger symptoms are limited to manageable levels. This approach leads to a more varied and nutritionally balanced diet, improved microbiome support, greater flexibility in social and everyday eating, and reduced stress around food choices.

As tolerance can change over time, previously problematic foods may be retested periodically.

This phase transforms the low FODMAP diet from a temporary clinical tool into a personalised, realistic lifestyle approach. The goal is not restriction, but personalisation and long-term dietary freedom.

Low FODMAP Foods: What can you eat?

Many naturally nutritious foods are low in FODMAPs, including:

• Carrots, potatoes, spinach, green beans, aubergine
• Rice, oats, quinoa
• Tofu, eggs, fish, meat
• Lactose-free dairy products, soy milk (made from soy protein), almond milk and rice milk
• Selected fruits such as bananas, blueberries, oranges
• Nuts such as peanuts, pecans, macadamias, walnuts

The Monash FODMAP App: A Practical Tool for Managing IBS

To help people navigate these serving-size considerations, Monash University has developed the Monash FODMAP App, a comprehensive resource based on the latest FODMAP research. The app provides an extensive food database with FODMAP ratings, recommended serving sizes, food reintroduction guidance, and practical tools for following the low FODMAP diet.

For many people with IBS, it is a trusted resource for identifying low FODMAP foods, understanding portion sizes, and supporting symptom management.

Why Monash University Is the Gold Standard for the Low FODMAP Diet

Monash University is the original developer of the low FODMAP diet and continues to lead global research in this field. The groundwork for this approach began in the early 2000s, when researchers at Monash University in Australia started investigating why many people with IBS experienced symptoms after eating certain carbohydrates, despite no visible damage in the digestive tract. Their work built on earlier scientific understanding that IBS is a functional gut–brain disorder, meaning symptoms are real but not caused by structural disease.

Through clinical trials and dietary studies, the Monash team identified a group of short-chain carbohydrates—later named FODMAPs—that are poorly absorbed in the small intestine and can trigger IBS symptoms in sensitive individuals. This discovery was a major breakthrough in nutrition science, as it shifted IBS management from general dietary advice to a structured, evidence-based dietary protocol.

Today, Monash University continues to lead this field by testing foods for FODMAP content in a laboratory, maintaining the official FODMAP food database, developing the Monash FODMAP App, and certifying selected low FODMAP products. This ongoing research ensures that recommendations are continuously updated based on new scientific evidence rather than outdated assumptions.

This makes Monash the gold standard for IBS nutrition science worldwide, providing the most reliable foundation for the low FODMAP diet and its clinical application.

Everyday Tips for Living with IBS

Living with IBS can sometimes feel unpredictable, but small daily habits can make a meaningful difference in managing symptoms and improving confidence around food.

One of the most effective strategies is to keep a symptom and food diary. Recording what you eat and how you feel can help identify patterns over time and make it easier to recognise personal triggers. Since IBS affects everyone differently, understanding your own responses is an important part of long-term symptom management.

Planning meals in advance can also help reduce stress and avoid digestive surprises. Having trusted options on hand makes it easier to stay consistent, particularly during busy periods or when eating away from home. Ready meals that align with low FODMAP principles, such as Froyda’s Monash-certified curries, stews, and soups, can provide a convenient and reliable option.

Eating slowly and choosing moderate portion sizes may also help reduce bloating and digestive discomfort. Taking time to eat mindfully can support digestion and make it easier to recognise feelings of fullness.

In addition, many people with IBS find it helpful to limit heavily processed foods and products high in added sugars, which can sometimes contribute to digestive symptoms. Instead, focusing on simple, balanced meals made from recognisable ingredients can help support overall gut comfort.

Finally, choosing foods that have been developed and reviewed according to low FODMAP principles can remove much of the guesswork from daily eating. Products such as Froyda’s Monash-certified low FODMAP meals offer a practical way to enjoy flavourful, convenient meals while staying aligned with a gut-friendly lifestyle.

• Keep a symptom & food diary to track triggers
• Plan meals ahead – ready meals help avoid digestive surprises
• Eat smaller portions slowly to reduce bloating
• Avoid heavily processed, sugary foods
• Choose tested products that are gut-friendly like Froyda’s Low FODMAP meals

How Froyda can help: Gut-Friendly Ready Meals

Following a low FODMAP diet in everyday life can be challenging, especially during busy routines, travel, or the elimination phase where ingredient control is most important. While the Monash University guidelines provide a clear scientific framework, many people still struggle to translate this into practical, enjoyable meals on a day to day basis.

At Froyda, we believe eating low FODMAP should be simple, enjoyable, and easy to maintain in everyday life. That’s why we create convenient, low FODMAP ready meals developed in alignment with the Monash University low FODMAP guidelines. All Froyda curries, stews, and soups are officially certified low FODMAP under Monash University’s recipe certification programme, meaning each recipe has been reviewed by the Monash team and adjusted where necessary to meet strict low FODMAP standards per serving.

Froyda helps make low FODMAP eating easier with convenient, Monash-certified meals designed for everyday life. Our ready-to-eat curries, stews, soups and sauces provide reliable low FODMAP options without the need for constant label checking, complicated meal planning, or uncertainty around ingredients. This helps reduce the day-to-day uncertainty often associated with IBS, especially when identifying safe foods or managing symptom-sensitive periods.

Our approach focuses on:

• Meals developed according to Monash Low FODMAP standards
• Carefully selected ingredients that avoid common high FODMAP triggers such as onion and garlic where required
• Balanced recipes designed for digestive comfort and everyday convenience

Explore our Monash-certified low FODMAP meals

Imortant Note

IBS is a complex condition, and diet is only one part of management. Stress, sleep, and lifestyle also play an important role.

The low FODMAP diet should ideally be followed with guidance from a qualified healthcare professional or dietitian to ensure nutritional balance and correct identification of food triggers.

Sources

Monash University FODMAP Team. About FODMAP and IBS. Monash FODMAP. https://www.monashfodmap.com/about-fodmap-and-ibs/

Monash University FODMAP Team. The 3 Phases of the Low FODMAP Diet. Monash FODMAP Blog.
https://www.monashfodmap.com/blog/3-phases-low-fodmap-diet/