Irritable bowel syndrome (IBS) is a common functional, chronic gastrointestinal disorder that causes recurrent abdominal discomfort and bowel symptoms, including abdominal cramps, change in bowel habit such as diarrhoea and/or constipation, wind and bloating. Other associated non-bowel-related symptoms include fatigue, headaches, bladder symptoms, and anxiety and depression. It is acknowledged that IBS is a disorder of the gut–brain axis and management of neuromodulation can often help patients (Vasant et al, 2021).
IBS is twice as common in women and affects 10–20% of the UK population, as well as accounting for up to 40% of referrals to gastroenterology for investigation. It is prevalent in 12% of the world's population, costing up to €8 billion in Europe (National Institute for Health and Care Excellence (NICE), 2017; Lacy and Patel, 2017; Vasant et al, 2021).
Diagnosis and causes
Diagnosis of IBS can be challenging due to the wide range of symptoms patients may experience, and there are various triggers exacerbating symptoms, which can vary over time. There may also be no clear origin of disease. The symptoms of IBS can mimic other gastrointestinal (GI) conditions, which can make diagnosis difficult. Usually, IBS is diagnosed as a result of a process of elimination of other GI disorders such as IBD, exocrine pancreatic insufficiency, bile acid diarrhoea and intolerances, cancer or, for female patients, conditions such as endometriosis, which can have similar symptoms.
The Rome IV criteria (Lacy and Patel, 2017) categorise IBS into different sub-types as per stool consistency (Table 1). These include IBS-C (constipation), IBS-D (diarrhoea), IBS-M (mixed) and IBS-U (unsubtyped) (Lacy and Patel, 2017; Vasant et al, 2021). However, the British Society of Gastroenterology (BSG) guidelines (Vasant et al, 2021) suggest that the NICE definition of IBS (abdominal pain or discomfort, bloating, in association with altered bowel habit, for at least 6 months, in the absence of alarm symptoms or signs) is more practical for diagnosis (Vasant et al, 2021). Patients are diagnosed with IBS if abdominal pain is relieved on defecation or have accompanying altered bowel habit and stool form. They must also suffer from two of the following symptoms: altered stool passage, bloating/distension or mucus, and symptoms that deteriorate when eating (NICE, 2017).
Table 1. Rome IV IBS diagnosis
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| IBS-C*≤25% of bowel movements of Bristol stool form types 1 or 2 and ≤25% of Bristol stool form types 6 or 7 | IBS-D≤25% of bowel movements of Bristol stool form types 6 or 7 and ≤25% of Bristol stool form types 1 or 2 | IBS-M≤25% of bowel movements of Bristol stool form types 1 or 2 and ≤25% of Bristol stool form types 6 or 7 ≤25% of bowel movements of Bristol stool form types 1 or 2 and ≤25% of Bristol stool form types 6 or 7 | IBS-UPatients who meet criteria for IBS but who do not fall into one of the other three subgroups according to Bristol stool form type |
IBS-D=IBS with diarrhoea; IBS-M=IBS with mixed bowel habits; IBS-U=IBS unclassified
IBS can be caused by a range of factors that can Impede treatment as the root cause may not be clear, including antibiotic use and infection, stress, genetics and early life events (Figure 1) (Black and Ford, 2020; Kumar, 2022). The condition is also thought to be a biopsychosocial disorder occurring due to a discord between the gut–brain axis. Causes could include altered central and autonomic nervous system modulation, altered visceral perception such as hypersensitivity, abnormal transit and motility due to change in serotonin metabolism. Additionally, it has been observed that patients with IBS can have issues with immune regulation, inflammation and gut permeability which can result following gastroenteritis (Black and Ford, 2020; Vasant et al, 2021).
Disruption of the microbiome has been attributed as a potential cause of IBS as episodes of gastroenteritis can trigger symptoms in addition to antibiotic use. The impact of changes on the gut microbiome can result in problems with visceral sensation and sensitivity, intestinal permeability, stool consistency and motility (Vasant et al, 2021). Further research is needed to ascertain cause and effect of this, and to investigate the benefits of probiotics in order to re-establish gut microbiome stability.
Management
Initial diagnosis of IBS should include the following tests: full blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and antibody testing for coeliac disease (NICE, 2017).
Patient–doctor interaction/relationship
IBS is a functional disorder for which management usually involves symptom control as there is no cure-all treatment available. Additionally, patients will have a variety of symptoms that can be debilitating and have a serious impact on day-to-day quality of life, social functioning and capacity to work (Vasant et al, 2021).
For initial management, it is acknowledged that it is beneficial to obtain a good patient–doctor relationship to enable a fruitful discussion around options to help minimise symptoms. As symptoms can vary according to the individual, IBS is often not well managed. As a result, patients feel unsupported, which can affect the management of their IBS and resulting quality of life (Halpert, 2018; Vasant et al, 2021). Patients report feeling frustrated due to lack of control, isolation and dissatisfaction with healthcare provision. Patients feel they may not be listened to and a survey of 1000 patients reported that only 47% of patients felt supported by their doctor during their IBS consultation (Black and Ford, 2020).
To improve patient–doctor interactions, which can have a positive effect on IBS symptoms, Halpert (2018) summarised vital elements for good communication during the patient–doctor consultation, as well as the importance of patient education to empower the patient to help manage their condition (Tables 2 and 3).
Table 2. Communication between patient and healthcare provider
| Elements of communication | How to | Example |
|---|---|---|
| Build the relationship | Greet warmlyElicit full agenda set priorities early in the interview | Use eye contact and smile when greeting the patient‘Is there anything else bothering you?’‘How can I help you the most today?’ |
| Listen actively | Start with open-ended questionsUse silence – repress the desire to respond with advice or an opinion (do not interrupt particularly in the first few minutes)Paraphrasing – rewarding a statement usually with less wordsClarifying – transforming unclear information into clear | ‘Tell me more about the pain’Non-verbal elements of active listening (directly face the person with open body relaxed posture, maintain eye contact, lean forward, head nodding)‘You had severe pain for a very long time’‘Sounds like you have seen many doctors and tried quite a few treatments without much success’ |
| Use empathyThe ability to understand the feelings of another person | Encourage emotional expressionIdentify and accept/validate feelingsDemonstrate empathy – verbally and non-verbally | ‘How does this situation make you feel?’‘I can see how difficult it has been for you to cope with these severe symptoms’‘It must be very frustrating to feel that no one understands’ |
| Elicit patient's perspective | Patient's beliefs regarding the illnessWhat is the impact on the quality of lifeDisease-related worries/anxiety | ‘What do you think is the cause of your illness?’‘How are these symptoms affecting your life?’‘What are you worried about in relation to your IBS?’ |
| Provide education | Elicit prior knowledge and educational needsCorrect misconceptionsFacilitate learning through problem solvingTest for comprehension | ‘What would you like to know about IBS the most?’‘IBS does not become cancer or colitis’‘Let's think what can you do if you are at work when the pain starts?’‘Can you tell me what you understood about this medication so far?’ |
| Negotiate a mutual treatment plan | Use patient's frame of referenceInvolve the patient in the decisionsExplore plan acceptability/barriersSet a realistic goalsEncourage questions | ‘You described the burning sensation that …’‘Which of the treatments we talked about are you most interested in trying?’‘What do you think will help the most?’‘Do you think you will be able to stick to this plan?’‘How can we make it easier?’‘Let's agree on working on making the symptoms better even though we may not be possible to make them go away completely’‘What questions do you have about …?’ |
Table 3. Patient education points
| Topic | Importance |
|---|---|
| IBS is a real gastrointestinal condition (not ‘in your head’)IBS can significantly affect one's life | Provides validation and demonstrates empathy |
| IBS is a chronic medical condition, although the symptoms can come and go. There is no magic pill for IBS | Helps patients set realistic expectations |
| There are many things we can do to help you better manage IBS symptomsYou may have long periods of time (sometimes years) without experiencing any symptoms | Provides hope to the patient, while implying the need for self-management |
| IBS does not cause cancer, colitis or any other problems. It does not shorten your life | Helps to clarify potential common misconceptions and reduce disease-related anxiety |
| For some people with IBS, stress can trigger symptoms or make them worse | Can be used to further explore the role of psychological factors in IBS |
| We need to work together to help you manage your IBS | Emphasises the need for a collaborative approach |
It is recommended that patients' expectations are managed and for them to be aware that there is no absolute cure for IBS, that it can be a process of trialling a variety of interventions and that management can include a combination of psychological, non-pharmacological and pharmacological therapies.
Management of symptoms
Primarily, the management of IBS is symptom control and the BSG guidelines for management of IBS provide evidence-based dietary recommendations in accordance with recommendations from NICE (2017) (Box 1).
Box 1.Dietary recommendations to manage IBS symptoms (adapted from NICE, 2017; Vasant et al, 2021)
- Regular meals and avoid missing meals
- Ideally eight cups of water or non-caffeinated drinks per day
- Maximum three cups per day of tea and coffee and restrict fizzy drinks and alcohol
- Reduce intake of high insoluble fibre foods (e.g. bran) and foods containing resistant starch
- Maximum three portions of fruit per day
- Avoid products with sorbitol if suffering from IBS-D
- If suffering with IBS-C increase soluble fibre (e.g. oats), starting at 3–4 g daily and build up to 20–30 g daily
First-line non-pharmacological recommendations include exercise and dietary advice. Exercise has been noted to improve gastrointestinal symptoms such as bloating, transit and gut microbe diversity, as well as having a positive impact on the gut–brain axis (Black and Ford, 2020). Around 80% of patients with IBS say their symptoms appear when certain foods are consumed and this can lead to 70% modifying their diet as a result. It has been recommended by BSG not to exclude foods due to IgG testing and not to follow a gluten-free diet unless the patient has a noted clinical intolerance, due to lack of evidence in these areas (Black and Ford, 2020; Vasant et al, 2021).
The FODMAP diet is second line following dietary advice (Figure 2). It recommends elimination of fermentable carbohydrates from the diet for 4–6 weeks, followed by a phased re-introduction period of trialling high FODMAP foods such as garlic and onion, and assessing individual tolerability under dietitian supervision. There is some evidence to show benefit of this diet in reducing symptoms in IBS; however, more quality evidence is needed to show long-term efficacy (Black and Ford, 2020; Vasant et al, 2021).
First-line pharmacological recommendations include probiotics, antimotility agents, laxatives, antispasmodics and peppermint oil. It should be recommended to patients to titrate doses of such agents to their own individual symptoms aiming for a type 4 stool as per the Bristol stool chart (NICE, 2017). Second-line pharmacological treatments are often only recommended by secondary care and include neuromodulators such as tricyclic antidepressants (TCAs) and serotonin reuptake inhibitors (SSRIs), as well as 5-Hydroxytryptamine 3 receptor (5HT3) antagonists.
There are a number of other medications recommended for IBS management in BSG guidelines but these have either been discontinued in the UK or are only available in the USA. These include eluxadoline, alosetron, lubiprostone, plecanatide and tegaserod. It is recommended by the BSG to trial medications for 3 months and to stop if no benefit is seen in this time (Vasant et al, 2021).
Antispasmodics
Antispasmodics are used to treat abdominal pain or spasms. They are divided into two groups: antimuscarinics and smooth muscle relaxants. Antimuscarinics include hyoscine butylbromide and dicycloverine but these have been found to cause more adverse effects in patients compared to smooth muscle relaxants alverine and mebeverine. Peppermint oil also has antispasmodic activity due to calcium channel blocking activity via L-Menthol but can cause reflux side effects (NICE, 2017; Black and Ford, 2020; Vasant et al, 2021).
Laxatives
There are a wide variety of laxatives available and doses should be titrated to patient response. First-line recommendations for IBS include osmotic and stimulant laxatives, although osmotic laxatives have been investigated predominantly in studies, particularly polyethylene glycol (PEG). However, these only showed benefit with treatment for 4 weeks, and long-term efficacy needs to be investigated further, as well as investigation of benefit for IBS-C using a wider range of laxatives (Black and Ford, 2020; Vasant et al, 2021). Lactulose is not recommended as a laxative to manage IBS-C as it can worsen symptoms such as bloating and distension (NICE, 2017).
‘Around 80% of patients with IBS say their symptoms appear when certain foods are consumed and this can lead to 70% modifying their diet as a result’
Second-line laxative recommendations include secretagogues such as linaclotide – a guanylate cyclase-C agonist that acts on intestinal epithelium, which helps to increase colonic transit and prucalopride, a selective serotonin 5HT4-receptor agonist with prokinetic properties. Linaclotide is recommended if patients have had treatment failure with other laxatives and have had persistent constipation for 12 months (NICE, 2017). Prucalopride is licensed for chronic constipation for treatment when other medications have failed, although trials of this medication in IBS-C patients are lacking (Vasant et al, 2021).
Antimotility agents
Loperamide is the first-line antimotility agent recommended by NICE. It is a synthetic μ-opioid agonist which binds to gut receptors to reduce peristalsis, allowing a prolonged gut transit time and reabsorption of water and electrolytes, as well as reducing urgency by increasing anal sphincter tone. Doses must be titrated to individual patient response in order to limit side effects like bloating and constipation (Vasant et al, 2021).
Studies have found 5HT3 receptor antagonists such as ondansetron to be useful at improving stool form, providing benefit for IBS diarrhoea; however, the evidence has not been thought to be sufficient for ondansetron to be recommended in British guidance yet. Other 5HT3 antagonists such as alosetron have been withdrawn in the UK due to severe constipation and ischaemic colitis risk (NICE, 2017). Rifaxamin is an antibiotic that has been explored to assess benefit in IBS-D as it reduces the growth of bacteria causing diarrhoea. There is a similarity in IBS and small intestinal bacterial overgrowth (SIBO) for which rifaxamin has been effective for in studies. This is currently not licensed in the UK for IBS-D (Black and Ford, 2020; Vasant et al, 2021).
Neuromodulators
Management of gut–brain axis dysfunction has increasingly been found to improve IBS symptoms, as patients often suffer with anxiety and depression. Selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) have been found to show benefit compared to placebo in trials in reducing IBS symptoms like abdominal pain and accompanying anxiety, although they did display greater incidence of side effects (Vasant et al, 2021).
NICE (2017) recommends starting a TCA as a second-line (unlicensed) agent if patients have failed to respond to first-line symptom management. It is suggested to start at low doses; for example, amitriptyline 5 mg at night and titrate up to a maximum of 30 mg at night if needed, assessing response on a regular basis. If patients have no success with TCAs or experience side effects, SSRIs (also unlicensed for IBS) can be trialled. It is recommended that patients' progress on these agents should be assessed at 4 weeks and then every 6–12 months, as per NICE guidance. It has been observed in practice that patients tend to end up on bigger doses than recommended in the guidelines; however, side effects can be limiting for the success of TCAs and SSRIs for IBS management (NICE, 2017).
There has been some suggestion that other neuromodulators such as serotonin noradrenaline reuptake inhibitors (SNRIs), duloxetine or pregabalin could have benefit in managing IBS, but further studies are required.
Probiotics
It has been suggested that the microbiome in patients with IBS can be impaired due to stress response, food elimination and antibiotics. The difficulty with probiotics is that they can sometimes cause a flare of symptoms during initial treatment, and knowing which strain and species are beneficial for each individual can be challenging (Black and Ford, 2020).
NICE recommends that if probiotics are trialled to manage IBS, they should be taken for at least 4 weeks to assess response, and the BSG recommends a 12-week trial. There are a variety of products available and evidence has shown different strains have various benefits depending on the type of symptoms the patient has. Bacillus coagulans GBI-30 improves frequency of stool in IBS-D and Saccharomyces cerevisiae (yeast) provides benefit for IBS-C, with Bifidobacterium improving intestinal health and reducing inflammation (Kumar et al, 2022). Probiotics are not regulated as medicinal products and vary with the strain combination and doses available, so it can be a case of trial and error to find a product that works for the patient.
Psychological management
The BSG (Vasant et al, 2021) recommends cognitive behavioural therapy (CBT) and gut-directed hypnotherapy as non-pharmacological interventions if patients have had no symptom improvement with medication therapy after 12 months.
More evidence is needed to explore whether psychological therapies have benefit earlier in the patient's IBS management journey (Vasant et al, 2021). NICE does not currently recommend alternative therapies such as acupuncture, homeopathy or reflexology for IBS management.
Refractory IBS
Refractory IBS is described as severe and chronic IBS, which has a degree of patient disability and lack of response to recommended treatments. At this point, it is important to try to limit further stress to the patient and subjection to further testing can do this; however, if symptoms are ongoing it should be considered if other functional GI conditions are the cause or are also involved overlapping with IBS.
At this point, the patient's diagnosis should be reviewed. A multi-faceted approach is needed, including various multidisciplinary interventions such as diet, medication and psychological therapies to manage refractory IBS (Vasant et al, 2021).
Conclusion
There are many gaps that still need exploring when considering the management of IBS. Unfortunately, it is not seen as a priority area for research funding, which is why treatment options are limited despite the large number of people who suffer with this condition. Some trials have looked at medications to help manage IBS, such as minesapride (5HT4 agonist) for IBS-C and the RELIEVE IBS D trial, which showed that enterosgel was safe and effective for the main symptoms of IBS-D. Consequently, enterosgel will be included in the next BSG IBS update (Howell et al, 2022). Faecal microbiota transplants are also being explored as a potential treatment option.
There is growing awareness and support for managing IBS on social media and television, as well as websites such as the IBS Network and their helpline. It is to be hoped that this, along with further research and evidence-based treatments, will increase awareness of the condition enabling patients to manage their IBS better and take control of debilitating symptoms.
Key Points
- Irritable bowel syndrome (IBS) is prevalent in the population yet is not managed well in practice due to a variety of reasons such as lack of research, patient factors and clinician expertise in managing functional conditions
- Good patient–medical practitioner relationship is key when managing IBS
- One size does not fit all. Patients vary widely in their experiences including triggers, symptoms and management strategies. Ensure to consider the gut–brain axis relationship
- Often a variety of strategies will be needed to manage IBS – medication alone may not be enough
- Further research is needed looking at management approaches including medications and psychological therapies