Initial publication date: 13 November 2026
Last reviewed: 13 November 2026
Next review due: 13 November 2027
Irritable bowel syndrome (IBS) is a common digestive condition affecting up to 30% of Australians. But if you live with ongoing bloating, abdominal pain, constipation or diarrhoea, you know it can affect much more than your gut. [7]
You might find yourself avoiding certain foods, planning your day around bathroom access or wondering whether something you ate will trigger symptoms. Perhaps you've already cut out dairy, gluten or other foods without finding much relief.
The good news is that there are ways to better understand and manage IBS. With the right support, you can work towards symptom relief while maintaining a nutritious, varied and enjoyable diet.
So, what exactly is IBS, and how can an Accredited Practising Dietitian (APD) help?
What is irritable bowel syndrome (IBS)?
Irritable bowel syndrome (IBS) is a disorder of gut–brain interaction (DGBI). This means that communication between the brain and digestive system is altered, affecting how the gut functions and how digestive sensations are experienced.
IBS is a genuine gastrointestinal condition. It is not simply stress, something you've eaten or a sign that your symptoms are imagined.
Several factors can contribute to symptoms, including changes in gut movement (motility), increased sensitivity within the digestive tract and altered gut–brain communication. Previous gastrointestinal infections, gut microbiome activity and psychological wellbeing may also play a role. [1,2]
IBS is a long-term condition, and symptoms can fluctuate over time. However, an individualised management approach can help many people improve their symptoms and quality of life.
What are the symptoms of IBS?
IBS symptoms vary between individuals. Some people mainly experience constipation, others experience diarrhoea, while some alternate between the two.
Common symptoms include:
Abdominal pain or cramping, which may be related to bowel movements.
Bloating or visible abdominal distension.
Excessive wind or flatulence.
Constipation or difficulty passing stools.
Diarrhoea or frequent, loose bowel movements.
A feeling of incomplete bowel emptying.
Urgency or changes in bowel habits.
Mucus in the stool.
Symptoms can fluctuate and may be influenced by meals, stress, sleep, hormonal changes, physical activity and other individual factors. [1,2]
Are there different types of IBS?
IBS is commonly grouped into four subtypes, based on predominant bowel habits:
IBS-C (constipation predominant): Constipation is the main bowel symptom.
IBS-D (diarrhoea predominant): Loose or watery stools are more common.
IBS-M (mixed): Alternating episodes of constipation and diarrhoea.
IBS-U (unclassified): Symptoms meet the criteria for IBS but don't fit neatly into the other subtypes. [1]
Understanding your IBS subtype can help guide treatment and symptom management.
What causes IBS?
There isn't one single cause of IBS. Instead, it is thought to involve a combination of factors affecting the gut, nervous system and digestive function. [1,2]
Some contributing factors include:
1. Altered gut–brain communication
The gut and brain are constantly communicating through nerves, hormones and other signalling pathways. Changes in this communication can influence gut movement, digestive sensations and sensitivity to pain.
2. Visceral hypersensitivity
Some people with IBS have increased sensitivity within the digestive tract. This means that normal processes, such as gas production or intestinal contractions, may be experienced as uncomfortable or painful.
3. Changes in gut motility
The movement of food and waste through the digestive tract can be altered, contributing to constipation, diarrhoea or unpredictable bowel habits.
4. Previous gastrointestinal infections
Some people develop IBS following gastroenteritis or food poisoning. This is known as post-infectious IBS and may involve changes in gut function, immune activity and the gut microbiome.
5. Gut microbiome changes
The gut microbiome is the community of microorganisms living within the digestive tract. Differences in microbial composition and activity have been observed in some people with IBS, although there is no single microbiome profile that explains the condition.
6. Stress and psychological factors
Stress and emotional wellbeing can influence gut–brain communication and digestive symptoms. This doesn't mean IBS is psychological or that symptoms are 'all in your head'. Rather, the gut and brain are closely connected, and both physical and psychological factors can affect symptoms.
Other factors, including medications, sleep disruption, hormonal fluctuations and pelvic floor dysfunction, may also be relevant for some people.
How is IBS diagnosed?
If you're experiencing ongoing digestive symptoms, it's important to speak with your GP rather than automatically assuming you have IBS.
A healthcare professional will assess your symptoms, medical history and any relevant investigations. IBS can be diagnosed using established symptom-based criteria alongside an appropriate clinical assessment. It is not necessary to rule out every possible condition before a positive diagnosis can be made. [1]
The Rome V criteria, updated in 2026, describe recurrent, but not continuous, abdominal pain or discomfort occurring on average at least three days per month over the previous three months, with symptoms beginning at least six months before diagnosis. The pain or discomfort must also be associated with at least two of the following:
Related to defaecation.
Associated with a change in stool frequency.
Associated with a change in stool form. [1]
Initial investigations may include a full blood count, C-reactive protein (CRP) and coeliac serology. Further testing depends on your symptoms and clinical presentation. [1]
This is important because other conditions, including coeliac disease, inflammatory bowel disease (IBD) and gastrointestinal infections, can cause symptoms that overlap with IBS.
When should you seek further medical assessment?
Some symptoms should not automatically be attributed to IBS. Speak with your GP if you experience:
Blood in your stool or rectal bleeding.
Unexplained weight loss.
Iron deficiency anaemia.
Persistent fever or vomiting.
Symptoms that regularly wake you from sleep.
Progressive or worsening abdominal pain.
A family history of bowel cancer, IBD or coeliac disease, particularly alongside new symptoms. [1]
Severe or rapidly worsening symptoms warrant prompt medical attention.
How can a dietitian help manage IBS?
Food can influence digestive symptoms, but there is no single IBS diet that works for everyone.
An APD can help you understand the relationship between food, bowel habits and digestive symptoms, while ensuring your diet remains nutritionally adequate, enjoyable and sustainable.
The goal isn't to eliminate as many foods as possible. It's to find the least restrictive approach that provides meaningful symptom relief.
1. Identifying individual food triggers
Rather than automatically cutting out entire food groups, a dietitian can help explore whether particular foods, ingredients, portions or eating patterns are contributing to your symptoms.
This may involve looking at:
Lactose and your individual tolerance to dairy products.
FODMAP-containing foods.
Fibre intake and the types of fibre you eat.
High-fat meals.
Caffeine, alcohol and spicy foods.
Artificial sweeteners and sugar alcohols.
Meal timing, portion sizes and eating habits.
A food and symptom diary may sometimes be useful, particularly when it has a clear purpose and doesn't encourage constant food monitoring.
Not every symptom is food-related, and a food that causes symptoms in one situation doesn't necessarily need to be avoided permanently. [1,3]
2. Improving fibre intake and bowel habits
Fibre plays an important role in digestive health, but the type, amount and rate of introduction can make a difference for people with IBS.
Soluble fibre, particularly psyllium, has evidence supporting its use in IBS. It absorbs water and forms a gel-like substance, which can help improve stool consistency and bowel regularity. [3]
Sources of soluble fibre include:
Oats.
Psyllium.
Chia seeds.
Some fruits, including kiwi fruit and oranges.
Legumes, depending on individual tolerance.
Some people find that large amounts of coarse or insoluble fibre, such as wheat bran, worsen their symptoms. However, this doesn't mean all higher-fibre foods need to be avoided.
A dietitian can help assess your current intake and gradually adjust the amount and types of fibre to support comfortable bowel movements.
3. Exploring the low-FODMAP diet
The low-FODMAP diet is one of the most researched dietary approaches for IBS. It can be helpful for people who continue to experience symptoms despite trying general dietary adjustments. Around three in four people with IBS report symptom improvement with a low-FODMAP approach, although it doesn't work for everyone. [3,4,7]
FODMAPs are a group of short-chain carbohydrates that are poorly absorbed in the small intestine and can be fermented by bacteria in the large intestine.
In some people with IBS, these carbohydrates can contribute to increased intestinal water content and gas production, which may trigger symptoms such as bloating, abdominal pain and altered bowel habits. [5]
Some common high-FODMAP foods include:
Onion and garlic.
Some wheat-based products.
Apples and pears.
Regular milk and some yoghurt products.
Certain legumes.
Some mushrooms, depending on the variety and serving size.
However, this doesn't mean these foods are unhealthy or that everyone with IBS needs to avoid them.
The low-FODMAP approach is a structured process involving three stages:
Stage 1: Restriction
Higher-FODMAP foods are temporarily replaced with suitable alternatives to assess whether reducing FODMAP intake improves symptoms. This phase is generally short-term, usually around 2–6 weeks.
Stage 2: Reintroduction
Individual FODMAP groups are systematically reintroduced to identify which types and quantities you tolerate. This helps establish your personal triggers rather than avoiding all FODMAPs.
Stage 3: Personalisation
Your diet is adapted to include as much variety as possible, limiting only the FODMAPs and quantities that genuinely cause problems. [5]
The aim is to move away from strict restriction and towards the most varied and flexible diet your digestive system can comfortably tolerate.
The low-FODMAP diet is not intended to be followed strictly for life. Working with a FODMAP-trained dietitian can help ensure the process is appropriate, nutritionally adequate and not unnecessarily restrictive. [3,5]
4. Supporting gut health and dietary variety
The gut microbiome plays an important role in digestion and other aspects of health. Dietary variety, particularly a range of fibre sources, helps provide nourishment for gut microorganisms.
However, people with IBS may find that increasing fibre or eating certain prebiotic-rich foods too quickly worsens symptoms.
A dietitian can help you gradually build dietary variety by exploring:
Different fruits and vegetables.
Wholegrains and oats.
Nuts and seeds.
Legumes and pulses.
Fermented foods, where tolerated.
Different sources of dietary fibre.
Probiotics are also frequently marketed for digestive health. However, evidence for their effectiveness in IBS remains inconsistent, and different strains and products may have different effects. They are not a universal treatment for IBS. [1,3]
The aim is to support long-term gut health without overlooking your current symptoms.
5. Looking beyond food
Although nutrition is an important part of IBS management, it isn't the only consideration.
Because IBS is a disorder of gut–brain interaction, a broader approach can be beneficial. Depending on your needs, this may include:
Establishing regular meal patterns.
Maintaining adequate hydration.
Reviewing caffeine and alcohol intake.
Supporting sleep and stress management.
Finding enjoyable ways to move your body.
Addressing food-related anxiety or fear of symptoms.
Where appropriate, your dietitian may recommend working alongside your GP, gastroenterologist, psychologist or pelvic health physiotherapist.
Gut-directed psychological therapies, including cognitive behavioural therapy (CBT) and gut-directed hypnotherapy, may also help improve IBS symptoms and quality of life. [1,6]
6. Preventing unnecessary dietary restriction
One of the most important aspects of IBS management is ensuring that symptom management doesn't come at the expense of nutritional adequacy or your relationship with food.
When digestive symptoms persist, it's understandable to start eliminating foods in an attempt to feel better. But progressively restricting your diet can sometimes lead to:
Reduced dietary variety.
Inadequate fibre intake.
Nutrient deficiencies.
Increased food-related anxiety.
Difficulty eating socially or away from home.
A more complicated relationship with food.
A dietitian can help identify which dietary changes are genuinely useful, where foods can safely be reintroduced and how to maintain a balanced, enjoyable diet.
The goal is always to find more options, not fewer.
Does everyone with IBS need to follow a low-FODMAP diet?
Absolutely not.
Although the low-FODMAP diet is supported by research, it isn't the only dietary strategy available and isn't necessarily the best starting point for everyone.
Some people experience meaningful improvements through simpler adjustments, such as:
Establishing more regular meal patterns.
Adjusting fibre intake.
Increasing soluble fibre.
Addressing lactose intolerance, where relevant.
Reviewing caffeine or alcohol intake.
Modifying meal sizes or fat intake.
Others may benefit from a structured or gentle low-FODMAP approach.
The most appropriate approach depends on your symptoms, nutritional status, dietary history, preferences and previous experiences with food restriction. Clinical guidance supports starting with general dietary advice before considering more specialised dietary interventions where needed. [3,4]
How can Eatwise Dietetics support you?
At Eatwise Dietetics, we understand that living with digestive symptoms can affect much more than what you eat.
Our approach to IBS management is individualised, evidence-based and centred around your goals.
We can help you:
Understand your digestive symptoms and potential contributing factors.
Identify individual food triggers without unnecessary restriction.
Improve fibre intake and bowel regularity.
Navigate the low-FODMAP diet, including reintroduction and personalisation.
Support nutritional adequacy and dietary variety.
Develop practical strategies that fit your lifestyle.
Build confidence around food and eating.
Whether you've recently been diagnosed with IBS or have been navigating symptoms for years, you don't have to figure everything out on your own.
You deserve to enjoy food without constantly worrying about how your gut will respond.
If you're looking for support with IBS or ongoing digestive symptoms, get in touch with us to discuss how we can help.
This article is intended for general educational purposes and does not replace individual medical or dietetic advice.
Further reading
References
Morrison S, Talley N. Diagnosis and management of irritable bowel syndrome. Australian Prescriber. 2026;49(3):93–98. https://doi.org/10.18773/austprescr.2026.018
Black CJ, Drossman DA, Talley NJ, Ruddy J, Ford AC. Functional gastrointestinal disorders: advances in understanding and management. The Lancet. 2020;396(10263):1664–1674. https://doi.org/10.1016/S0140-6736(20)32115-2
Vasant DH, Paine PA, Black CJ, Houghton LA, Everitt HA, Corsetti M, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021;70:1214–1240. https://doi.org/10.1136/gutjnl-2021-324598
Cuffe MS, Staudacher HM, Aziz I, Coss Adame E, Krieger-Grubel C, Madrid AM, et al. Efficacy of dietary interventions in irritable bowel syndrome: a systematic review and network meta-analysis. The Lancet Gastroenterology & Hepatology. 2025;10(6):520–536. https://doi.org/10.1016/S2468-1253(25)00054-8
Monash University. IBS diets: the low FODMAP diet. Monash FODMAP. https://www.monashfodmap.com/ibs-central/diets/
Thakur ER, Khasawneh M, Moayyedi P, Black CJ, Ford AC. Efficacy of behavioural therapies for irritable bowel syndrome: a systematic review and network meta-analysis. The Lancet Gastroenterology & Hepatology. 2025;10(12):1075–1088. https://doi.org/10.1016/S2468-1253(25)00238-9
Dietitians Australia. Irritable bowel syndrome (IBS). https://dietitiansaustralia.org.au/health-advice/irritable-bowel-syndrome-ibs
Acknowledgement of Country
Eatwise Dietetics acknowledges the Traditional Custodians of the lands on which we live and work. We honour their deep and ongoing connections to Country, lands, waters, culture and community. We pay our respects to Elders past and present and recognise the importance of Indigenous knowledge in caring for Country and sustaining food systems for future generations.