Changes

July 2025 — minor update. Links to IBS Network have been removed.

Update

Goals

To support primary healthcare professionals to:

• Make a positive diagnosis of irritable bowel syndrome after exclusion of other causes of similar symptoms.
• Identify red flag indicators and refer people appropriately.
• Advise on self-help measures for symptom relief.
• Manage symptoms with drug treatment when appropriate.
• Arrange referral for dietary advice or mental health support, if needed.

Outcome measures

Audit criteria

QOF indicators

QIPP - Options for local implementation

NICE quality standards

The following National Institute for Health and Care Excellence (NICE) quality standards are relevant to this CKS topic:

• Statement 1. Adults with symptoms of irritable bowel syndrome are offered tests for inflammatory markers as first-line investigation, to exclude inflammatory causes.
• Statement 2. Adults with symptoms of irritable bowel syndrome are given a positive diagnosis, if no red flag indicators are present and investigations identify no other cause of symptoms.
• Statement 3. Adults with irritable bowel syndrome are offered advice on further dietary management, if their symptoms persist after they have followed general lifestyle and dietary advice.
• Statement 4. Adults with irritable bowel syndrome agree their follow-up with their healthcare professional.

[NICE, 2016]

What is it?

• Irritable bowel syndrome (IBS) is a chronic, relapsing, and often debilitating disorder of gut-brain interaction.
• Typical clinical features are abdominal pain which:
  • Is associated with a change in stool form and/or frequency.
  • May be related to defaecation.
  • May be associated with bloating.
• IBS may be classified by the predominant stool type (according to the Rome IV criteria) into the following sub-types which exist on a spectrum depending on the person's quantity, intensity, and severity of different symptoms:
  • Diarrhoea predominant (IBS-D) — the commonest sub-type.
  • Constipation predominant (IBS-C).
  • Mixed, fluctuating between diarrhoea and constipation (IBS-M).
  • Unclassified (IBS-U) — symptoms meet the criteria for IBS but do not fall into one of the three subgroups above according to Bristol stool type.

[Drossman, 2016; NICE, 2017; Pimentel, 2018; Ford, 2020; Lacy, 2021; Vasant, 2021]

What causes irritable bowel syndrome?

• The pathophysiology of irritable bowel syndrome (IBS) is complex and not fully understood, but is likely to be multifactorial involving the interplay of biological, psychological, and social factors.
• Possible mechanisms 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.
• Possible causes or risk factors include:
  • Enteric infection.
    • Post infectious IBS is observed in about 10% of people following acute enteric infection (bacterial, viral, or protozoal).
  • Genetic.
    • Twin studies and family studies confirm familial aggregation of IBS, and a US case-control study found a person with a first-degree relative with IBS had an odds ratio of 2.75 of developing the condition themselves [Saito, 2010].
    • Shared childhood experiences and/or environmental exposures within families may confound findings.
  • Gastrointestinal inflammation (for example, secondary to inflammatory bowel disease).
  • Dietary factors (such as alcohol, caffeine, spicy, and fatty foods).
    • Up to 90% of people report that food triggers symptoms.
  • Drugs, such as antibiotics.
  • Psychological comorbidity (such as stress, anxiety and/or depression)
    • Psychosocial factors influence the physiological functioning of the gastrointestinal tract via the brain-gut axis, and may affect the person's pain experience, symptom behaviour, expectations of treatment, and clinical outcome.

[Ford, 2014a; Chey, 2015; Halland, 2015; McKenzie, 2016; Drossman, 2016; McKenzie, 2016; Pimentel, 2018; Barbara, 2019; Black, 2020; Ford, 2020; Eijsbouts, 2021; Fukudo, 2021; Vasant, 2021]

How common is it?

• The prevalence of IBS in the general population is estimated to be 5–20% but as many people with symptoms do not seek medical advice this may be an underestimate [NICE, 2017].
• Estimates of prevalence vary widely depending on study methodology and diagnostic criteria used:
  • A recent Rome Foundation global survey (n = 73,076) reported a worldwide prevalence of IBS of 4.1% when Rome IV diagnostic criteria were used compared to 10.1% when the less restrictive Rome III criteria were used [Sperber, 2021; Vasant, 2021].
  • A systematic review and meta-analysis of population-based studies reported a pooled prevalence of IBS (in over 80,000 adults from 34 countries) using Rome IV criteria as 3.8% compared to 9.2% using Rome III criteria [Oka, 2020].
• IBS most commonly affects young people aged 20–39 years, and prevalence decreases with increasing age.
• Several studies have reported a higher prevalence of IBS in females compared to males, including:
  • A systematic review and meta-analysis of population-based studies (30 studies using Rome III criteria) which reported an odds ratio (OR) of 1.46 (95% CI 1.33 to 1.59) in females compared with males [Oka, 2020].
  • Another large systematic review of population-based studies (n = 188,229) which reported a pooled OR of 1.67 in women compared with men (95% CI, 1.53 to 1.82) [Lovell, 2012].
  • The Rome Foundation global survey which also identified a higher pooled prevalence of IBS in women compared with men using Rome IV criteria (OR 1.8; 95% CI 1.7 to 2.0) [Sperber, 2021].
• Reported prevalence varies widely between countries — one systematic review and meta-analysis of population-based studies found prevalence to range from 0.2% in India to 21.2% in the USA (using Rome IV criteria) [Oka, 2020].
  • It is not clear if variation in prevalence between countries is due to genuine differences between countries or to methodological variation between studies.

[Ford, 2012; Halland, 2015; NICE, 2017; Pimentel, 2018; Moayyedi , 2019; Black, 2020; Black, 2020; Ford, 2020]

What is the prognosis?

• The symptoms of irritable bowel syndrome (IBS) may fluctuate over years, and a systematic review of observational longitudinal studies with follow-up for a median of two years found [El-Serag, 2004]:
  • 2–18% of people had worsening IBS symptoms.
  • 30–50% of people's symptoms remained unchanged.
  • 12–38% of people's symptoms improved.
  • Following initial negative investigations, fewer than 5% of people were diagnosed with an alternative organic gastrointestinal disorder at follow-up.
• People with post-infectious IBS may have an improved prognosis compared with those with typical IBS:
  • Symptoms resolve spontaneously in about 50% of affected people within 6–8 years of the index infection [Spiller, 2012].
• A poorer prognosis may be associated with [El-Serag, 2004]:
  • Longer duration of symptoms.
  • Previous history of surgery.
  • Higher somatic scores.
  • Co-morbid anxiety and depression.

When should I suspect irritable bowel syndrome?

• Suspect irritable bowel syndrome (IBS), in the absence of alarm symptoms or signs, if any of the following symptoms have been present for at least 6 months:
  • Abdominal pain or discomfort, or
  • Bloating, or
  • Change in bowel habit.
• Consider the possibility of alternative conditions with similar symptoms:
  • All people with suspected IBS should be assessed for symptoms and signs of serious conditions that may present with similar clinical features to IBS such as bowel cancer, ovarian cancer or inflammatory bowel disease.
  • Alarm symptoms and signs include unintentional and unexplained weight loss, rectal bleeding, positive faecal immunochemical test (FIT), change in bowel habit over the age of 60 years, raised faecal calprotectin, iron deficiency anaemia, persistent or frequent bloating in females (especially if aged over 50 years), abdominal or rectal mass or family history of bowel cancer, ovarian cancer, coeliac disease, or inflammatory bowel disease.
  • For more information see the CKS topics on Coeliac disease, Crohn’s disease, Gastrointestinal tract (lower) cancers - recognition and referral, Ovarian cancer and Ulcerative colitis.
• Make a diagnosis of IBS in primary care if abdominal pain or discomfort has been present for at least 6 months and:
  • Is either relieved by defecation or associated with altered bowel frequency (increased or decreased), or stool form (hard, lumpy, loose, or watery) and:
  • Is accompanied by at least two of the following symptoms:
    • Altered stool passage (straining, urgency, incomplete evacuation).
    • Abdominal bloating (more common in women than men), distension, tension or hardness.
    • Made worse by eating.
    • Passage of mucus.
  • Alternative conditions with similar symptoms have been excluded.
• Be aware that extra-intestinal features are common in people with IBS including:
  • Lethargy, nausea, back pain, headache, gynaecological, and bladder symptoms.
• In secondary care, the more restrictive ROME IV criteria for IBS (developed by expert consensus) are often used for diagnosis.
  • ROME IV criteria: Recurrent abdominal pain, on average, at least 1 day per week in the last 3 months (with symptom onset at least 6 months prior to diagnosis) which is associated with two or more or the following:
    • Related to defaecation;
    • Change in frequency of stool;
    • Change in stool form.
  • Patients are sub-grouped according to predominant Bristol stool type to help direct treatment:
    • 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.

How should I assess a person with suspected irritable bowel syndrome?

If a diagnosis of irritable bowel syndrome (IBS) is suspected, assess the person:

• Take a history, asking about:
  • Symptoms including:
    • Onset and duration.
    • Type and severity — showing people the Bristol Stool Form Scale may help with description of stool form.
    • Clinical features suggestive of an alternative diagnosis, including a serious or life-threatening condition — arrange admission or referral where appropriate. For more information see the CKS topics on Coeliac disease, Crohn’s disease, Gastrointestinal tract (lower) cancers - recognition and referral, Ovarian cancer and Ulcerative colitis.
  • The person's diet (including fibre intake), nutrition, and any known food triggers (such as alcohol, caffeine, spicy and fatty foods).
    • Consider the use of a food diary to determine an association between specific foods and symptoms.
  • Other potential triggers including enteric infection, recurrent antibiotic use, recent stress, anxiety, or depression.
    • See the CKS topic on Generalized anxiety disorder and Depression for more information.
  • Comorbidities (including psychological and previous surgery) and medications (including opioids).
  • The impact of symptoms on daily functioning such as home, work, school, and leisure activities.
  • The person's exercise and physical activity levels.
• Examine the person:
  • Check weight, calculate the body mass index (BMI), and assess for unintended or unexplained weight loss.
  • Palpate the abdomen for signs of tenderness or masses.
  • Perform a rectal examination, with the person's consent, to exclude perianal or rectal pathology.
• Consider arranging the following investigations to exclude an alternative diagnosis:
  • Full blood count (FBC) — to assess for anaemia, and a raised platelet count.
  • Inflammatory markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) — may be raised if there is active inflammation or infection.
  • Coeliac serology — to exclude coeliac disease, particularly if there is diarrhoea-predominant IBS or mixed symptoms. For more information see the CKS topic on Coeliac disease.
  • Faecal calprotectin — in particular if the person has diarrhoea and is aged 45 years or younger to exclude inflammatory bowel disease. For more information see the CKS topics on Crohn’s disease and Ulcerative colitis.
  • Local and national referral guidelines for suspected colorectal or ovarian cancer should be followed, where indicated.
• Discuss with/refer to gastroenterology people with:
  • Atypical presentations such as nocturnal diarrhoea or abdominal pain.
  • Features of a defecatory disorder (such as a sensation of incomplete, or blocked evacuation and use of digital manoeuvres to facilitate defaecation).
  • Faecal incontinence.

What else might it be?

Alternative conditions which may present similarly to irritable bowel syndrome include:

• Malignancy (such as colorectal cancer, small bowel cancer, ovarian cancer and lymphoma) — see the CKS topic on Gastrointestinal tract (lower) cancers - recognition and referral and Ovarian cancer for more information.
• Other causes of constipation, such as:
  • Functional or drug-induced constipation — see the CKS topic on Constipation for more information.
  • Hypothyroidism — see the CKS topic on Hypothyroidism for more information.
• Other causes of diarrhoea, such as:
  • Inflammatory bowel disease — see the CKS topics on Crohn's disease and Ulcerative colitis for more information.
  • Coeliac disease — see the CKS topic on Coeliac disease for more information.
  • Gastrointestinal infection and secondary lactose intolerance — see the CKS topic on Gastroenteritis for more information.
  • Antibiotic-associated diarrhoea (for example Clostridium difficile colitis) — see the CKS topic on Diarrhoea - antibiotic associated for more information.
  • Microscopic colitis — more common in females over the age of 45 years. Often presents with coexisting autoimmune disease, nocturnal or severe watery diarrhoea and weight loss and may be precipitated by some medications such as NSAIDs, SSRIs, or proton pump inhibitors.
  • Bile acid malabsorption — a past medical history including cholecystectomy or right hemicolectomy may be suggestive of bile acid diarrhoea.
  • Hyperthyroidism — see the CKS topic on Hyperthyroidism for more information.
  • Laxative misuse.
• Other causes of abdominal pain or discomfort, such as:
  • Diverticular disease — see the CKS topic on Diverticular disease for more information.
  • Chronic pancreatitis — see the CKS topic on Pancreatitis - chronic for more information.
  • Gallstones — see the CKS topic on Gallstones for more information.
  • Peptic ulcer disease — see the CKS topic on Dyspepsia - proven peptic ulcer for more information.
  • Gastro-oesophageal reflux disease — see the CKS topic on Dyspepsia - proven GORD for more information.
• Other causes of symptoms, such as:
  • Premenstrual syndrome and endometriosis — see the CKS topics on Premenstrual syndrome and Endometriosis for more information.
  • Anxiety and/or depression — see the CKS topics on Generalized anxiety disorder and Depression for more information.

Scenario: Management of irritable bowel syndrome

From age 18 years onwards.

Laxatives

• The National Institute for Health and Care Excellence (NICE) guideline Irritable bowel syndrome in adults: diagnosis and management [NICE, 2017] recommends that laxatives from any class (apart from lactulose) can be tried in people with IBS-C and should be titrated according to symptoms.
  • Lactulose should be avoided as it may increase gas production and therefore exacerbate symptoms.
  • For information on prescribing laxatives, see the CKS topic on Constipation.
• Second line treatments for constipation (such as linaclotide) should only be considered if optimal or maximum tolerated doses of previous laxatives from different classes have not helped and the person has had constipation for at least 12 months [NICE, 2017].
  • Local prescribing guidelines may vary — in some areas linaclotide may be initiated in secondary care.

Linaclotide

Second line treatments for constipation (such as linaclotide) should only be considered if optimal or maximum tolerated doses of previous laxatives from different classes have not helped and the person has had constipation for at least 12 months [NICE, 2017].

• Dose for adults with moderate to severe irritable bowel syndrome with constipation:
  • Linaclotide 290 micrograms once daily, dose to be taken at least 30 minutes before meals.
• Treatment should be reviewed if there is no response after 4 weeks.
• Linaclotide is not licensed for use in children or adolescents.

[ABPI, 2022; BNF, 2022]

Loperamide

• Loperamide is licensed for the symptomatic treatment of acute diarrhoea in irritable bowel syndrome (IBS) in adults aged 18 years and older. The recommended dose is:
  • Initially 4 mg, followed by 2 mg for up to five days, dose to be taken after each loose stool; usual dose 6–8 mg daily; maximum 16 mg per day.

[ABPI, 2020; BNF, 2022]

Antispasmodic drugs

Antispasmodic drugs may be used as required for abdominal pain or spasm in irritable bowel syndrome (IBS). Drug options include:

• Direct-acting smooth muscle relaxants such as mebeverine hydrochloride (immediate-release or modified-release), alverine citrate, and peppermint oil.
  • These drugs are less likely to cause adverse effects compared with antimuscarinics such as hyoscine butylbromide and dicycloverine.
  • Alverine citrate — for an adult a dose of 60–120 mg one to three times a day may be used.
  • Mebeverine hydrochloride, for an adult:
    • 135–150 mg three times a day, dose preferably taken 20 minutes before meals for immediate-release preparation.
    • 200 mg twice daily for modified-release preparation.
  • Peppermint oil — for an adult, one to two capsules taken three times a day for up to 2–3 months if needed, dose to be taken before meals, swallowed whole with water.

[BNF, 2022]

Antidepressant drugs

• Tricyclic antidepressants (TCAs) such as amitriptyline, may be used for the management of pain associated with irritable bowel syndrome (off-label indication).
  • The National Institute for Health and Care Excellence (NICE) recommends starting treatment at a low dose, for example, amitriptyline 5–10 mg at night, and titrating the dose up in steps of 10 mg at least every 2 weeks if needed, to a maximum of 30 mg at night [NICE, 2017].
• Selective serotonin reuptake inhibitors (SSRIs) such as sertraline, citalopram or fluoxetine are second-line drug options (off-label indication).
  • NICE recommend that SSRIs are only considered in people who do not respond to a tricyclic antidepressant [NICE, 2017].
  • NICE and British Society of Gastroenterology (BSG) guidelines do not specify an SSRI of choice.
• The BSG [Vasant, 2021] recommend advising patients that TCAs or SSRIs are being used at low doses for their pain modulatory properties and peripheral effects on gastrointestinal function, rather than at a dose used to treat common mental disorders.
• For prescribing information on TCAs and SSRIs see the CKS topic on Depression.

[NICE, 2017; Vasant, 2021; BNF, 2022]

Search strategy

Scope of search

A literature search was conducted for guidelines, systematic reviews and randomized controlled trials on primary care management of irritable bowel syndrome.

Search dates

September 2017 - March 2022

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline.

• exp irritable bowel syndrome/, ibs.tw, irritable bowel syndrome.tw
• (irritable bowel adj (syndrome$ or disease$ or IBS).ti,ab.

Sources of guidelines

• National Institute for Health and Care Excellence (NICE)
• Scottish Intercollegiate Guidelines Network (SIGN)
• Royal College of Physicians
• Royal College of General Practitioners
• Royal College of Nursing
• NICE Evidence
• World Health Organization
• Guidelines International Network
• TRIP database
• Agency for Healthcare Research and Quality
• National Health and Medical Research Council (Australia)
• Royal Australian College of General Practitioners
• British Columbia Medical Association
• Canadian Medical Association
• Alberta Medical Association
• Michigan Quality Improvement Consortium
• Singapore Ministry of Health
• National Resource for Infection Control
• RefHELP NHS Lothian Referral Guidelines
• Medline (with guideline filter)
• Driver and Vehicle Licensing Agency
• NHS Health at Work (occupational health practice)

Sources of systematic reviews and meta-analyses

• The Cochrane Library:
  • Systematic reviews
  • Protocols
  • Database of Abstracts of Reviews of Effects
• Medline (with systematic review filter)
• EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

• NIHR Health Technology Assessment programme
• The Cochrane Library:
  • NHS Economic Evaluations
  • Health Technology Assessments
• Canadian Agency for Drugs and Technologies in Health
• International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

• The Cochrane Library:
  • Central Register of Controlled Trials
• Medline (with randomized controlled trial filter)
• EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

• Drug and Therapeutics Bulletin
• TRIP database
• Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

• Department of Health
• Health Management Information Consortium (HMIC)

Patient experiences

• Healthtalk
• BMJ - Patient Journeys

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

• British National Formulary (BNF)
• electronic Medicines Compendium (eMC)
• European Medicines Agency (EMEA)
• Medicines and Healthcare products Regulatory Agency (MHRA)
• REPROTOX
• Scottish Medicines Consortium
• Stockley's Drug Interactions
• TERIS
• TOXBASE
• Micromedex
• UK Medicines Information

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

• Clinical accuracy.
• Consistency with other providers of clinical knowledge for primary care.
• Accuracy of implementation of national guidance (in particular NICE guidelines).
• Usability.

Principles of the consultation process

• The process is inclusive and any individual may participate.
• To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
• Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
• Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
• External reviewers are not paid for commenting on the draft topics.
• Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
• All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
• All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

Stakeholders

• Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
• Stakeholders identified from the following groups are invited to review draft topics:
  • Experts in the topic area.
  • Professional organizations and societies (for example, Royal Colleges).
  • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
  • Guideline development groups where the topic is an implementation of a guideline.
  • The British National Formulary team.
  • The editorial team that develop MeReC Publications.
• Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

Patient engagement

Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

• Topic selection
• Scoping of topic
• Selection of clinical scenarios
• First draft internal review
• Second draft internal review
• External review
• Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

• Animal studies
• Original research is not written in English

Possible exclusions for reviewed literature:

• Sample size too small or study underpowered
• Bias evident or promotional literature
• Population not relevant
• Intervention/treatment not relevant
• Outcomes not relevant
• Outcomes have no clear evidence of clinical effectiveness
• Setting not relevant
• Not relevant to UK
• Incorrect study type
• Review article
• Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

• Feasibility
  • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
• Organizational and Financial Impact Analysis
• Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
  • Eligible population
  • Current interventions
  • Likely uptake of new intervention or recommendation
  • Cost of the current or new intervention mix
  • Impact on other costs
  • Condition-related costs
  • In-direct costs and service impacts
  • Time dependencies
• Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

• Personal financial interests
• Personal family interest
• Personal non-financial interest
• Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.