As part of IBS Awareness month, we're spotlighting a different aspect of IBS symptom management. This week, we're focussing on IBS and diet.

Irritable bowel syndrome (IBS) is described as a chronic and often deliberating disorder of the gut-brain axis. It is characterised by symptoms of recurrent abdominal pain and disordered defecation. IBS is diagnosed using Rome IV criteria which states that patients with IBS will follow the following symptoms;

- Report on average abominable pain once weekly in association with a change if stool frequency, a change in stool food and/or relief or worsening of abdominal pain related to stool defecation

IBS symptoms are also commonly associated with a negative impact on the patient’s quality of life.

Rome IV diagnostic criteria for IBS
Recurrent abdominal pain on average at least 1 day/week in the last 3 months associated with 2 or more of the following criteria
1. Related to defecation
2. Associated with a change in the frequency of stool
3. Associated with a change in the appearance of stool

The management of IBS

Patients with IBS symptoms can be recommended several strategies to help manage their symptoms including dietary, lifestyle and supplements. We are going to explore the use of dietary management for IBS.

Dietary management in IBS

When you receive a diagnosis for IBS it can feel overwhelming on where to start and how to get control of your symptoms. Commonly I see people cutting our large food groups from their diet, often gluten and/or dairy, to help control their symptoms. However, this is not something I advise. Cutting out large food groups from your diet can result in nutritional deficiencies and often it will leave you just as confused as to what is affecting your symptoms!

Therefore, my first line of advice is to keep a food and symptom diary to assess the effect of food on your symptoms. This does not have to include weighing out everything you eat, just an overview of your meals. See an example below –






Bowl of porridge with oat milk, banana and honey

Cup of black coffee

Tuna and sweetcorn sandwich on wholegrain bread

Packet of ready salted crisps

Tea with soya milk and one sugar

White pasta with tomato sauce and meatballs

Yogurt with berries

Cadbury’s fruit and nut bar


Symptoms experienced:

Bloating 1 hour after lunch

Gas in the evening after dinner

Download your free four week food and symptom tracker here.

Keeping a food and symptom diary will help you identify any foods that may be triggering your IBS symptoms. You can then exclude just these foods and keep track of your symptoms. Certain foods and drinks are especially triggering for peoples IBS symptoms, these include-

• Spicy food
• Very fibrous foods including onions and pulses (peas, lentils and beans)
• Cruciferous vegetables (broccoli, cabbage, cauliflower)
• High fat, high sugar foods
• Caffeinated drinks (coffee, energy drinks)
• Alcohol
• Sweeteners

If you are unable to find any links between certain foods/drinks and your IBS symptoms, you can consider following a low FODMAP diet.

One of the most popular and well known dietary interventions for IBS is following the low FODMAP diet. To understand the reasoning behind this diet we first need to cover what exactly “FODMAP’ is.

FODMAPs stands for –


FODMAPs are a class of small non-digestible carbohydrates, which are poorly absorbed in the small bowel. When these FODMAP foods are consumed they lead to water secretion into the gastrointestinal (GI) tract and fermentation (by our friendly bacteria), this produces gases that can lead to distension in the gut and trigger a number of related IBS symptoms including bloating and abdominal pain.

FODMAPs foods are relatively common and are found in a wide range of foods such as fruits, vegetables, legumes and cereals, honey, milk and dairy products and sweeteners.

To find out what foods count as low and high FODMAP, check out this resource.

The low FODMAP diet involves removing these food groups from your diet until symptoms subside and then slowly introducing these foods back into your diet to create a personalised diet for the individual.

Stages of a low FODMAP diet
1. Removal of high FODMAP foods from your diet and replacement with low FODMAP alternatives (roughly 4-8 weeks)
2. Gradual reintroduction of foods into the diet whilst assessing symptoms
3. Personalisation of diet to avoid foods that trigger symptoms

FICTION – the low FODMAP diet should be a long term strategy

This is a common mistake I see when people are following the low FODMAP diet. The low FODMAP diet is not a long term solution, it is very restricted and can result in you missing key nutrients. Therefore it should only be followed for a short amount of time until symptoms have disappeared, at which point you start introducing these FODMAP foods to find an amount that works for you.

FICTION – I can carry out the low FODMAP diet myself

The low FODMAP diet should always be carried out alongside a healthcare professional. This is because the diet is very restricted and can result in nutrient deficiencies. A healthcare professional will work alongside you to ensure you are still following a healthy balanced diet whilst on the low FODMAP diet.

FICTION – everyone with IBS should follow the low FODMAP diet

Whilst the low FODMAP diet is one of the most well0known strategies for IBS management, it is not the only one. Patients with IBS should be aware of all the possible interventions for IBS management to find the one that works for them and their lifestyle.

FICTION – All FODMAP foods will trigger my IBS symptoms

Whilst all FODMAP foods are a potential trigger, it does not mean that every FODMAP food will result in IBS symptoms. The response to FODMAP foods will differ between patients. This is why a personalised approach is so important when it comes to IBS – not everyone will react the same!

Takeaways –

  • First line management for IBS should be a food and symptom diary (alongside other clinical assessments) before cutting out foods unnecessarily
  • A low FODMAP diet can be used to help manage IBS symptoms but this should always be carried out alongside a healthcare professional and it is not a long term strategy – the goal is to find a personalised diet
  • The low FODMAP diet can be very restricted and can be a very significant change for indivuduals therefore patients should always outweigh the cost vs benefit
  • Dietary changes are not the only ways to manage IBS symptoms, lifestyle changes and the use of supplements can also be used

For more information on managing your IBS symptoms through dietary changes, you can book a free 1-1 consultation with our nutrition team via this link.


References –

Lacy, B., Pimentel, M., Brenner, D., Chey, W., Keefer, L., Long, M. and Moshiree, B., 2020. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. American Journal of Gastroenterology, 116(1), pp.17-44.

Ford AC, Lacy BE, Talley NJ. Irritable bowel syndrome. N Eng J Med 2017;376:2566–78.
Drossman DA, Hasler WL. Rome IV-functional GI disorders: Disorders of gut-brain interaction. Gastroenterology 2016;150:1257–61.

Ford AC, Moayyedi P, Lacy BE, et al. American College of Gastroenterology monograph on the management of irritable bowel syndrome and chronic idiopathic constipation. Am J Gastroenterol 2014;109(Suppl 1):S2–26.

Lacy BE, Mearin F, Chang L, et al. Bowel disorders. Gastroenterology 2016;150:1393–407.

Bellini, M., Tonarelli, S., Nagy, A., Pancetti, A., Costa, F., Ricchiuti, A., de Bortoli, N., Mosca, M., Marchi, S. and Rossi, A., 2020. Low FODMAP Diet: Evidence, Doubts, and Hopes. Nutrients, 12(1), p.148.