Intended for healthcare professionals

Practice Guidelines

Irritable bowel syndrome in adults in primary care: summary of updated NICE guidance

BMJ 2015; 350 doi: (Published 25 February 2015) Cite this as: BMJ 2015;350:h701
  1. Cheryl Hookway, technical analyst1,
  2. Sara Buckner, technical analyst2,
  3. Paul Crosland, health economist2,
  4. Damien Longson, consultant liaison psychiatrist3
  1. 1National Institute for Health and Care Excellence, Clinical Guideline Updates Team, Manchester M1 4BT, UK
  2. 2National Institute for Health and Care Excellence, Clinical Guideline Updates Team, London, UK
  3. 3Department of Psychiatry, Manchester Mental Health and Social Care Trust, Manchester, UK
  1. Correspondence to: C Hookway cheryl.hookway{at}

The bottom line

  • Consider using the low FODMAP diet for patients whose irritable bowel syndrome symptoms persist despite following general lifestyle and dietary advice from a healthcare professional with relevant expertise

  • Consider linaclotide (laxative) for people with chronic constipation if other laxatives haven’t worked and they have had constipation for at least 12 months, but ensure adequate follow-up to evaluate its effectiveness

  • Consider tricyclic antidepressants (TCAs) if laxatives, loperamide, or antispasmodics have not helped, and then selective serotonin reuptake inhibitors if TCAs are ineffective

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder with an estimated prevalence of 10-20%.1 The condition mostly affects people aged 20-30 years and is twice as common in women as in men.1 It can be painful and debilitating, lead to feelings of anxiety and depression, and negatively affect quality of life.1

This article summarises the most recent recommendations from the National Institute for Health and Care Excellence (NICE) on irritable bowel syndrome in adults in primary care.2


NICE recommendations are based on systematic reviews of best available evidence and explicit consideration of cost effectiveness. Where the evidence was minimal, recommendations in the original guidance were based on the guideline development group’s experience and opinion of what constitutes good practice. Changes in this update are based on evidence from updated systematic reviews and updated evidence on cost effectiveness. Evidence levels for the recommendations are given in italic in square brackets.

Initial assessment

  • Consider assessment for IBS if the person reports having had any of the following symptoms for at least six months:

    • -Abdominal pain or discomfort

    • -Bloating

    • -Change in bowel habit.

  • Ask all people presenting with possible symptoms of IBS if they have any of the following “red flag” indicators and refer them to secondary care for further investigation if any are present:

    • -Unintentional and unexplained weight loss

    • -Rectal bleeding

    • -Family history of bowel or ovarian cancer

    • -A change in bowel habit to looser or more frequent stools (or both) persisting for more than six weeks in a person aged over 60 years.

  • Assess all people presenting with possible IBS symptoms for the following red flag indicators and refer them to secondary care for further investigation if any are present:

    • -Anaemia

    • -Abdominal masses

    • -Rectal masses

    • -Markers of inflammatory bowel disease.

  • Measure serum CA125 in primary care in women with symptoms that suggest ovarian cancer in line with the NICE guideline on ovarian cancer (clinical guideline 122).3

  • Consider a diagnosis of IBS only if the person has abdominal pain or discomfort that is relieved by defecation or is associated with altered bowel frequency or stool form. This should be accompanied by at least two of the following four symptoms:

    • -Altered stool passage (straining, urgency, incomplete evacuation)

    • -Abdominal bloating (more common in women than in men), distension, tension, or hardness

    • -Symptoms made worse by eating

    • -Passage of mucus.

  • Other features such as lethargy, nausea, backache, and bladder symptoms are common in people with IBS and may be used to support the diagnosis.

  • [All based on moderate and low quality evidence from randomised controlled trials (RCTs) and controlled trials.]

Diagnostic tests

  • In people who meet the IBS diagnostic criteria, undertake the following tests to exclude other diagnoses:

    • -Full blood count

    • -Erythrocyte sedimentation rate or plasma viscosity

    • -C reactive protein

    • -Antibody testing for coeliac disease (endomysial antibodies or tissue transglutaminase antibodies).

  • The following tests are not necessary to confirm the diagnosis in people who meet the IBS diagnostic criteria:

    • -Ultrasound

    • -Rigid or flexible sigmoidoscopy

    • -Colonoscopy, barium enema

    • -Thyroid function test

    • -Faecal ova and parasite test

    • -Faecal occult blood

    • -Hydrogen breath test (for lactose intolerance and bacterial overgrowth).

  • [All based on moderate and low quality evidence from RCTs and controlled trials.]

Dietary and lifestyle advice

  • Provide people with IBS with information that explains the importance of self help in effectively managing their condition. This should include information on general lifestyle, physical activity, diet, and symptom targeted medication such as laxatives and antimotility agents.

  • Encourage people to identify and make the most of their available leisure time and to create relaxation time.

  • For people with low levels of physical activity, provide brief advice and counselling to encourage them to increase their activity levels.

  • Assess diet and nutrition and provide the following general advice:

    • -Have regular meals and take time to eat

    • -Avoid missing meals or leaving long gaps between eating

    • -Drink at least eight cups of fluid a day, especially water or other non-caffeinated drinks, such as herbal teas

    • -Restrict tea and coffee to three cups a day

    • -Reduce intake of alcohol and fizzy drinks

    • -It may be helpful to limit intake of high fibre food (such as wholemeal or high fibre flour and breads, cereals high in bran, and wholegrains such as brown rice)

    • -Reduce intake of “resistant starch” (starch that resists digestion in the small intestine and reaches the colon intact), which is often found in processed or re-cooked foods

    • -Limit fresh fruit to three portions (about 80 g each) a day

    • -People with diarrhoea should avoid sorbitol, an artificial sweetener found in sugar-free sweets (including chewing gum) and drinks, and in some diabetic and slimming products

    • -People with wind and bloating may find it helpful to eat oats (such as oat based breakfast cereal or porridge) and linseeds (up to one tablespoon a day).

  • Review fibre intake, adjusting (usually reducing) it while monitoring the effect on symptoms. Discourage people from eating insoluble fibre (such as bran). If an increase in dietary fibre is advised, people should take soluble fibre such as ispaghula powder or eat foods high in soluble fibre (for example, oats).

  • Advise people who choose to try probiotics to take the product for at least four weeks, at the dose recommended by the manufacturer, while monitoring the effect.

  • Discourage the use of aloe vera in the treatment of IBS.

  • Do not encourage use of acupuncture or reflexology in the treatment of IBS.

  • [All based on moderate and low quality evidence from RCTs and controlled trials.]

Low FODMAP diet

The low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet restricts dietary short chain carbohydrates, which are poorly absorbed in the small intestine and fermented in the large intestine. These can be found in wheat, some fruit and vegetables, beans and pulses, artificial sweeteners, and some processed foods. Fermentation is not specific to people with IBS but is considered to worsen symptoms in people with IBS who have visceral hypersensitivity.

  • If a person’s IBS symptoms persist while following general lifestyle and dietary advice offer advice on further dietary management. Such advice should:

    • -Include single food avoidance and exclusion diets—for example, a low FODMAP diet (Updated recommendation.)

    • -Be given only by a healthcare professional with expertise in dietary management. (New recommendation.)

  • [Based on very low quality RCTs and controlled trials.]

Pharmacological therapy

  • Decisions about pharmacological management should be based on the nature and severity of symptoms. The recommendations made below assume that the choice of single or combination drugs is determined by the predominant symptom(s).

  • Consider prescribing antispasmodic agents. These should be taken as needed, alongside dietary and lifestyle advice.

  • Consider laxatives for the treatment of constipation in people with IBS, but discourage people from taking lactulose.

  • Loperamide should be the first choice of antimotility agent for diarrhoea in people with IBS.

  • Advise people with IBS how to adjust their doses of laxative or antimotility agent according to the clinical response. Titrate the dose according to stool consistency, with the aim of achieving a soft, well formed stool (corresponding to Bristol stool form scale type 4).

  • [All based on moderate, low, and very low quality RCTs.]

  • Consider tricyclic antidepressants (TCAs) as second line treatment for people with IBS if laxatives, loperamide, or antispasmodics have not helped. (At the time of publication TCAs did not have a UK marketing authorisation for this indication.) TCAs are mainly used for treatment of depression but are recommended here only for their analgesic effect. Start at a low dose (5-10 mg equivalent of amitriptyline), taken once at night, and review regularly. The dose may be increased but does not usually need to exceed 30 mg. (Reviewed 2015, unchanged.) [Based on very low quality RCTs.]

  • Consider selective serotonin reuptake inhibitors (SSRIs) only if TCAs are ineffective. (Reviewed 2015, unchanged.) [Based on very low quality RCTs.]

  • Take into account the possible side effects when offering TCAs or SSRIs to people with IBS. Follow up people taking either of these drugs for the first time at low doses for the treatment of pain or discomfort in IBS after four weeks and then every six to 12 months. (Reviewed 2015, unchanged.) [Based on very low quality RCTs.]


Linaclotide, a guanylate cyclase C receptor agonist, is one of a relatively new class of laxatives that is licensed for moderate to severe IBS with constipation at a dose of 290 µg once daily.

  • Consider linaclotide for people with IBS only if:

    • -Optimal or maximum tolerated doses of laxatives from different classes have not helped and

    • -The person has had constipation for at least 12 months. (New 2015.)

  • Follow up people taking linaclotide after three months. (New 2015.)

  • [All based on moderate to very low quality RCTs.]


Lubiprostone, a chloride channel (CIC-2) agonist is also one of a relatively new class of laxatives and is licensed for chronic idiopathic constipation “when lifestyle changes are inadequate” at a dose of 24 µg once or twice daily. However no recommendation was made owing to a lack of quality evidence on effectiveness. (2015.)

Psychological interventions

  • Consider referral for psychological interventions (cognitive behavioural therapy (CBT), hypnotherapy, or psychological therapy (or a combination)) in people who do not respond to drug treatments after 12 months and who develop a continuing symptom profile (described as refractory IBS). [Based on moderate to very low quality RCTs.]

  • No other recommendation was made on the psychological interventions of relaxation, computerised CBT, and mindfulness therapy owing to a lack of quality evidence on effectiveness. (Reviewed 2015, unchanged.)

Complementary and alternative medicine

  • The use of acupuncture should not be encouraged for the treatment of IBS. [Based on moderate to low quality RCTs.]

  • The use of reflexology should not be encouraged for the treatment of IBS. [Based on one moderate quality RCT.]


  • Follow-up should be agreed between the healthcare professional and the person with IBS, based on the response of the person’s symptoms to interventions. This should form part of the annual patient review. The emergence of any red flag symptoms during management and follow-up should prompt further investigation or referral to secondary care. [Based on consensus of the guideline development group; no relevant studies identified.]

Overcoming barriers

Implementation tools and resources to help you put the guideline into practice can be found at

Although practice and service delivery may vary, it is not anticipated that there will be major barriers to implementing these recommendations. Organisations should evaluate their own practices to identify any local barriers and develop actions for overcoming them.

Potential concerns or barriers include:

  • Insufficient numbers of healthcare professionals with expertise in delivering low FODMAP advice to meet the demand for this popular dietary intervention

  • Linaclotide costs more than other laxatives that are currently used to treat constipation predominant IBS.

How patients were involved in the creation of this article

Committee members involved in this guideline update included lay members who contributed to the formulation of the recommendations summarised here.

Further information on the guidance

The 2008 National Institute for Health and Care Excellence guideline on irritable bowel syndrome (IBS) in adults (Clinical guideline 61)4 was reviewed as part of NICE’s routine surveillance programme to determine whether it needed updating. These surveillance reports identified new evidence on the role of antidepressants, relaxation therapy, the newer treatments linaclotide and lubiprostone (laxatives), and the low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet.


This update was carried out in 2015 by a committee made up of standing members and a small number of topic experts with knowledge and experience of IBS. Two standing members and one topic expert are general practitioners (see below for full list of names and roles).

For full details on methods for this update, refer to the interim process and methods guide and the guidelines manual 2012.5 6

Systematic reviews were conducted for four review questions: on antidepressants, low FODMAP diet, laxatives (linaclotide and lubiprostone), and psychological interventions (relaxation, computerised cognitive behavioural therapy, and mindfulness therapy). The quality of the evidence was appraised using the grading of recommendations, assessments, developing, and evaluation (GRADE) approach.7 8

A systematic literature search was undertaken to identify health economic evidence within published literature relevant to the review questions. No economic evaluations were identified for any of the review questions. The committee made a qualitative judgment about cost effectiveness by considering expected differences in resource use and relevant UK NHS unit costs alongside the results of the clinical review of the evidence of effectiveness.

Stakeholders were invited to comment on a draft version of the updated guidance, and the final version of the update took these comments into account.

NICE has produced four different versions of the guideline: an addendum to the 2008 full version containing new and updated recommendations2; a pathway (; a version known as the “NICE guideline” that summarises the recommendations, including those that have been updated (; and a version for patients and the public ( All these versions are available from the NICE website.

Future research
  • What is the clinical effectiveness and cost effectiveness of low dose tricyclic antidepressants and selective serotonin reuptake inhibitors for treating IBS in primary care?

  • What is the clinical and cost effectiveness of a low FODMAP diet in treating IBS?

  • What is the clinical and cost effectiveness of computerised cognitive behavioural therapy and mindfulness therapy for the management of IBS in adults?


Cite this as: BMJ 2015;350:h701


  • This is one of a series of BMJ summaries of new guidelines based on the best available evidence; they highlight important recommendations for clinical practice, especially where uncertainty or controversy exists.

  • The members of the committee were Damien Longson (chair), Catherine Briggs (GP), John Cape (director of psychological therapies programme), Alun Davies (surgeon), Alison Eastwood (health service researcher), Sarah Fishburn (lay member), Jim Gray (microbiologist), Nuala Lucas (anaesthetist), Kath Nuttall (NHS management), Tilly Pillay (neonatal medicine), Nick Screaton (radiologist), Lindsay Smith (GP), Philippa Williams (lay member), Sophie Wilne (paediatric oncologist)—all standing members; Mark Follows (GP with specialist interest in gastroenterology), Else Guthrie (professor of psychological medicine), Yvonne McKenzie (dietitian with specialist interest gastroenterology), Marion Saunders (lay member), Simon Smale (consultant gastroenterologist), Peter Whorwell (professor of medicine and gastroenterology)—all topic specific members. The technical team at NICE comprised Sara Buckner, Paul Crosland, Cheryl Hookway, Roberta Richey, and Toni Tan.

  • Contributors: All authors were part of the committee that made the recommendations described here. CH drafted the summary and SB, PC, and DL revised it critically for important intellectual content. All authors approved the final version. All authors are guarantors.

  • Funding: CH, SB, and PC are employees of NICE, which is funded by the Department of Health to develop clinical guidelines. DL received a fee from NICE for chairing the committee that made the recommendations described in this summary. No authors received specific funding to write this summary.

  • Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following interests: CH, SB, and PC are employed by NICE; CH is a member of the British Dietetic Association and a registered dietitian; DL is a director of research and innovation for Manchester Mental Health and Social Care Trust and a committee chair for NICE. The authors’ full statements can be viewed at

  • Provenance and peer review: Commissioned; not externally peer reviewed.


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