IBS Awareness Month: clinical insights and considerations
Each year, IBS Awareness Month takes place throughout April. The campaign is supported by the NHS and Guts UK! and aims to raise awareness, reduce stigma and support people living with IBS to manage their symptoms effectively.
Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder that often causes changes in bowel habits, bloating and abdominal pain. IBS is usually a lifelong condition where symptoms can fluctuate in presence and severity over time. [1,2] Other symptoms can include fatigue and nausea. Appetite or enjoyment of food may be affected, which may be caused by the symptoms above. Food aversion or meal anxiety may affect some people with IBS, where eating in general or certain foods can be associated with the onset or worsening of symptoms.
While IBS is not life-threatening, it can affect quality of life. Effective treatment, however, can help to alleviate or manage symptoms.
The exact prevalence of the disorder is unknown, but up to 20% of the population is affected by IBS symptoms at some point in their lives. [3] The disorder mostly affects people between the ages of 20 and 39, with prevalence decreasing in older population groups.3 Prevalence appears to be higher in females than in males. [3]
Causes and triggers
The causes of IBS are not fully understood but are likely to be multifactorial. IBS is a functional gastrointestinal disorder, meaning that symptoms occur due to abnormal gut function rather than visible structural damage. The possible mechanisms of this include:
Visceral hypersensitivity
Abnormal gastrointestinal immune function
Changes in gut microbiome
Abnormal autonomic activity
Abnormal central pain processing of afferent gut signals (altered 'brain-gut interactions')
Abnormal gastrointestinal motility
Other factors may play a role in the development of IBS. These include: [4]
Post-infectious changes – IBS may develop after an acute gastrointestinal infection.
Genetic influences – There may be an increased risk of developing IBS where there is a first-degree relative with the condition.
Dietary sensitivities – Trigger foods include high-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) foods, fatty foods, caffeine and alcohol.
Stress and psychological factors – depression, anxiety and stress can exacerbate IBS symptoms.
Not all IBS is the same!
There are no specific tests to diagnose IBS; however, symptom type/frequency/prevalence, blood tests and stool samples should be included in the diagnosis process. NICE guidance on IBS diagnosis and management is available, which should be followed to ensure other clinical conditions such as coeliac disease, bowel/ovarian cancer or inflammatory bowel disease are ruled out.5
The ROME IV criteria are used for IBS diagnosis and patients are grouped into the following based on Bristol stool type.
IBS with diarrhoea (IBS-D)
IBS with constipation (IBS-C)
IBS with mixed bowel habits (IBS-M)
IBS unclassified (IBS-U), where symptoms meet the criteria for IBS but do not fall into one of the three subgroups above according to Bristol stool type
This helps to identify the most appropriate treatment options.
Treatment options
Treatment can be a very personalised affair, which may include dietary, lifestyle, pharmacological and/or psychological approaches.
Adequate hydration and small, frequent meals are recommended for anyone with IBS symptoms. Engaging in healthy eating habits, including a range of tolerated foods, can help manage symptoms.
Some people may benefit from limiting caffeine and/or alcohol, avoiding spicy or fatty foods, or manipulating the type and amount of fibre in the diet.1 The need to consider these things will depend on the type of symptoms present.
Dietary triggers are often identified and discussed by those who are living with IBS, who may also be tempted to remove trigger foods from their diet. However, exclusion diets should be discussed and managed with the support of a registered dietitian to ensure nutritional adequacy and reintroduction where possible.
Let’s take a look at the common dietary approaches used in the management of IBS.
1. Low-FODMAP diet
This diet reduces the intake of short-chain fermentable carbohydrates, which may cause bloating and gas in some people.
Developed over the past 20 years by Monash University, this approach may work for about two-thirds of IBS patients.1
For more information and resources on FODMAPs, visit: About FODMAPs and IBS | Monash FODMAP - Monash Fodmap
A 2022 review of the efficacy of the low-FODMAP diet in IBS highlighted that it achieved significant improvements in symptoms over a habitual diet and was superior to other interventions.5 The diet ranked first for improving abdominal pain severity, abdominal bloating or distension severity and bowel habits, although for the latter it was not superior to any other intervention.
A further review conducted in 2024, which looked at the overall role of diet in IBS management, also acknowledged that the low-FODMAP diet can improve gastrointestinal symptoms and quality of life for IBS patients.6
However, both reviews recognised the limitations of the included studies. Common issues included subject adherence to the diet being inconsistent and a lack of specific information regarding the FODMAP content of the diet. Most trials were based in secondary or tertiary care and did not study the effects on symptoms of FODMAP reintroduction.5,6
2. The Mediterranean diet
The Mediterranean diet has been studied for its health benefits in relation to a range of conditions and general health. However, there has been great interest in its potential beneficial effects on IBS symptoms.
Characterised by a limited intake of processed foods, sugar and saturated fats, with regular consumption of fruits, vegetables, wholegrains, nuts, legumes and olive oil, and moderate intakes of fish, meat, eggs and fermented dairy products, the Mediterranean diet has been shown to have anti-inflammatory effects.
This has been of interest in IBS management as inflammation is a contributory mechanism for symptom development.
Studies have shown that adherence to the Mediterranean diet can improve IBS symptoms over habitual diet. [6] However, the diet may not be suitable for all patients with IBS, and it may need to be personalised to achieve a suitable dietary profile depending on the patient’s symptom type. [7]
3. Probiotics
The gut microbiome can be altered in people with IBS and probiotics have been explored as a potential treatment option. However, there is limited conclusive data to identify the most beneficial strains or combinations of probiotics to effectively manage IBS symptoms. [8]
Whilst the jury is still out, probiotics may be worth a try. NICE recommends trialling probiotic supplementation for at least four weeks and monitoring the effects. [9]
Other things to consider
Medications
Medications may be used to manage symptoms. [9] These may be prescribed if diet and lifestyle changes are not effective. Over-the-counter options are also available:
Antispasmodics, eg mebeverine, alverine, and hyoscine butylbromide
Peppermint oil capsules to help relieve spasms
Laxatives for constipation, with the option of linaclotide where there are persistent symptoms (Lactulose is not generally advised in IBS management)
Diarrhoea management, eg loperamide, ondansetron
Low-dose tricyclic antidepressants (TCAs) for pain modulation and mood improvement and as a possible secondary treatment if laxatives, loperamide or antispasmodics have not helped
Selective serotonin reuptake inhibitors (SSRIs) - prescribed if TCAs have not been effective
Stress management and regular activity
Regular exercise is beneficial for everyone and should be encouraged in those with IBS, too. Activities such as walking and yoga can promote relaxation and mindfulness, which may help to reduce symptom severity.
Stress management can play a role in the management of IBS. [10]
Evidence suggests that IBS symptoms are linked with psychological factors. [10] This is attributed to the complex world of the gut-brain axis. This incorporates a range of communication pathways between the two, including neutral pathways, immune signalling, endocrine/metabolic pathways and microbial influence.
Supporting gut and brain health through diet, lifestyle and targeted interventions may help to alleviate IBS symptoms. NICE recognises that psychological interventions, such as cognitive behavioural therapy (CBT), hypnotherapy and/or psychological therapy, should be considered for people with IBS who do not respond to pharmacological treatments after 12 months and who develop a continuing symptom profile (described as refractory IBS). [9]
Conclusion
IBS is a complex, fluctuating and multifactorial condition, where there is no single definitive treatment option. Effective IBS treatment requires a patient-centred approach, which may need to integrate dietary modification, medication options, psychological support and ongoing education to manage symptoms. Acknowledging this complexity is essential, as it supports tailored strategies that aim to not only reduce symptoms but also improve overall quality of life.
Emma has been a Registered Dietitian for over 18 years and has experience in adult and paediatric dietetics. She has been the Editor of NHD for 10 years, steering the editorial content and supporting the production process. Emma currently works in industry.
Emma Coates, RD
References:
NHS (2025). Irritable bowel syndrome (IBS) Irritable bowel syndrome (IBS) - NHS
NICE (2025). Irritable bowel syndrome: How Common is it? Prevalence | Background information | Irritable bowel syndrome | CKS | NICE
Causes | Background information | Irritable bowel syndrome | CKS | NICE. https://cks.nice.org.uk/topics/irritable-bowel-syndrome/background-information/causes/
NICE (2025). Irritable bowel syndrome: When should I suspect irritable bowel syndrome? Diagnosis | Diagnosis | Irritable bowel syndrome | CKS | NICE
Jayasinghe M et al. The Role of Diet in the Management of Irritable Bowel Syndrome: A Comprehensive Review. 20240316-20345-1c8wkad.pdf
Chen EY, et al (2024). The Association Between a Mediterranean Diet and Symptoms of Irritable Bowel Syndrome. The Association Between a Mediterranean Diet and Symptoms of Irritable Bowel Syndrome - ScienceDirect
Goodoory VC, et al (2023). Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis. Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis - ScienceDirect
NICE (2008). Irritable bowel syndrome in adults: diagnosis and management. Clinical guideline CG6. Recommendations | Irritable bowel syndrome in adults: diagnosis and management | Guidance | NICE
NHS Reform (2025). IBS and your mental health. IBS and your mental health | NHS inform
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