• Assess for red flag indicators and refer for further investigation if present.
• Assess the person's diet and lifestyle and offer advice accordingly.
• Consider drug treatment with single or combination therapies, according to the person's predominant symptoms:
• Antispasmodics for abdominal pain and cramp.
• Antimotility drugs for people with diarrhoea.
• Laxatives for people with constipation.
• Advise people to adjust doses of laxative or antimotility drug according to response, to achieve a soft, well-formed stool.
• If symptoms do not respond to first-line treatment:
• Consider a trial of a low dose tricyclic antidepressant, or a selective serotonin reuptake inhibitor if a tricyclic antidepressant has previously been shown to be ineffective.
• Refer to secondary care anyone who presents with a red flag indicator (see Differential diagnosis).
• Consider referral if:
• There is uncertainty about the diagnosis.
• The person has health-related anxieties that have not been allayed.
• The person is following general lifestyle and dietary advice without clear benefit — refer to a registered dietitian for advice and treatment (including single food avoidance and exclusion diets).
• There is no response to diet, lifestyle, and drug treatments after 12 months — consider referral for psychological interventions.

For details of diagnosing irritable bowel syndrome and excluding other causes of symptoms, see Diagnosis.

• Assess the type and severity of symptoms.
• Assess the person for the presence of red flag indicators (see Differential diagnosis).
• Assess the person's diet and nutrition:
• Is there anything in the diet that triggers symptoms?
• Review fibre intake. (What type of fibre and how much?)
• Assess the person's physical activity levels, ideally using the the General Practice Physical Activity Questionnaire (GPPAQ).
• Assess the person's lifestyle and psychological status.
• Have they recently experienced any psychological or physical stress?
• Are they depressed or anxious?

• The General Practice Physical Activity Questionnaire (GPPAQ) is intended for use in adults (16–74 years of age) in routine general practice to provide a simple, 4-level Physical Activity Index (PAI) reflecting an individual's current physical activity. The index can be used to help inform the decision as to when interventions to increase physical activity might be appropriate.
• The GPPAQ can be downloaded from the Department of Health website (www.dh.gov.uk).

Basis for assessing red flag indicators

• The National Institute for Heath and Clinical Excellence (NICE) guidance Irritable bowel syndrome in adults recommends that all people with possible irritable bowel syndrome (IBS) should be assessed for red flag indicators and referred to secondary care for further investigation if any are present [NICE, 2005; National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].

Basis for assessing symptoms

• Assessment of bowel habits and stool characteristics will enable the healthcare professional to determine whether the person has diarrhoea-predominant IBS, constipation-predominant IBS, or mixed IBS [Mayer, 2008]. This will guide the person's management.

Basis for assessing diet

• The NICE guidance Irritable bowel syndrome in adults recommends that diet and nutrition should be assessed in all people with IBS [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].
• The role of dietary modification in the management of IBS is uncertain. Dietary manipulation in the form of avoidance of specific foods may offer improvement for up to two-thirds of people with IBS [National Collaborating Centre for Nursing and Supportive Care, 2008].
• Single food avoidance diets and exclusion diets should only be undertaken on the advice of a dietitian [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].
• The NICE guidance Irritable bowel syndrome in adults recommends that healthcare professionals should review the fibre intake of all people with IBS [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].

Basis for recommending assessment of physical activity using the General Practitioner Physical Activity Questionnaire (GPPAQ)

• Public health intervention guidance from NICE recommends that primary care practitioners should use a validated tool (such as the Department of Health's GPPAQ) to identify inactive individuals [NICE, 2006].

Basis for assessing lifestyle

• IBS is often associated with psychological distress. Both initial presentations and exacerbations of IBS are often preceded by psychological stressors or physical stressors (e.g. gastrointestinal infection) [Spiller, 2007; Mayer, 2008].

• Encourage people with irritable bowel syndrome (IBS) to try to identify sources of stress, and discuss ways to create relaxation time.
• Give general advice regarding diet.
• High fibre diets are not recommended for people with IBS.
• Advise the person to adjust their fibre intake according to their symptoms:
• Fibre intake often needs to be reduced in people with IBS. Advise people to reduce their intake of insoluble fibre, such as wholemeal or high fibre flour and breads, cereals high in bran, and whole grains such as brown rice.
• If more fibre is needed, recommend soluble fibre supplements (e.g. ispaghula) or foods high in soluble fibre (e.g. oats).
• Consider a trial of wheat or lactose exclusion — seek advice from a registered dietitian before starting single food avoidance and exclusion diets.
• Give people with low physical activity levels brief advice and counselling to increase their activity levels.
• Adults should aim to do 30 minutes of moderate intensity physical activity on at least 5 days of the week.
• This can be achieved either by doing all the daily activity in one session, or by doing several sessions of at least 10 minutes.
• The activity can be lifestyle-based (e.g. climbing stairs, walking, or cycling), structured exercise (e.g. attending a dance class or fitness training session), sport, or a combination of these.
• Increased physical activity may not be appropriate for people with diarrhoea-predominant IBS, and people with certain medical conditions.
• Discuss the use of probiotics where appropriate. Advise people who wish to try probiotics to choose one brand and:
• Take them for at least 4 weeks while monitoring the effect.
• Take them at the dose recommended by the manufacturer.

There is a lack of good quality evidence on the role of lifestyle modification in the management of irritable bowel syndrome.

• These recommendations are consistent with the National Institute for Health and Clinical Excellence guidance Irritable bowel syndrome in adults [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].

Basis for encouraging people to create relaxation time

• Stress commonly aggravates irritable bowel syndrome (IBS). Around half of IBS outpatients attribute the onset of symptoms to a stressful event [National Collaborating Centre for Nursing and Supportive Care, 2008].

Basis for not recommending a high fibre diet

• Based on their clinical experience of adverse effects of a high fibre diet in people with IBS, the Guideline Development Group (GDG) unanimously agreed that the practice in primary care of recommending high fibre diets to people with IBS should stop [National Collaborating Centre for Nursing and Supportive Care, 2008].

Basis for modifying fibre intake

• Evidence from nine RCTs (n = 545) shows that significantly more people have improved global symptoms of IBS when taking fibre compared with placebo.
• Subgroup analysis suggests that soluble fibre is more effective than insoluble fibre.
• Evidence from several small RCTs suggests that fibre does not significantly improve pain or bowel habit compared with placebo.
• Evidence from one RCT (n = 80) suggests that fibre increases bloating compared with placebo.
• Evidence from two RCTs (n = 281) shows that significantly more people have improved global symptoms of IBS when taking soluble fibre compared with insoluble fibre; however there is no significant difference in pain or in improvement in bowel habits.
• The consensus of the GDG was that insoluble fibre should not be recommended for people with IBS as it is ineffective in the management of symptoms and may even increase symptoms in some people [National Collaborating Centre for Nursing and Supportive Care, 2008].
• The GDG suggested that GPs should investigate the person's usual fibre intake with a view to modifying fibre levels to suit the symptom profile and they should monitor the person's response to dietary modification [National Collaborating Centre for Nursing and Supportive Care, 2008].
• It may be preferable for the dietary fibre intake to be closer to 12 grams per day than 18 grams per day.

Basis for considering a trial of wheat or lactose exclusion

• The role of dietary modification in the management of IBS is uncertain. Some experts recommend a trial of wheat or lactose exclusion [Spiller, 2007; Spiller et al, 2007], although there is little evidence to support this.
• Approximately 10% of people with IBS have lactose intolerance [Spiller et al, 2007]. There is weak evidence from one RCT (n = 70) that a lactose restricted diet produces a significant difference in symptom score in people with lactose intolerance, but not in those who are tolerant of lactose [Bohmer and Tuynman, 1996].
• In people with IBS, wheat consumption is often associated with increased symptoms which may be due to the content of fibre, fructans, or resistant starch. Increasing the variety of other cereals and reducing, but not necessarily excluding, wheat may be beneficial [National Collaborating Centre for Nursing and Supportive Care, 2008].

Basis for recommending that exclusion diets only be undertaken under supervision of a registered dietitian

• The GDG was concerned that excluding individual foods or complete food groups without appropriate supervision can readily lead to inadequate nutrient intakes and ultimately malnutrition. In addition, symptoms often remain unresolved leading to further inappropriate dietary restriction [National Collaborating Centre for Nursing and Supportive Care, 2008].

Basis for recommending an increase in physical activity in people with IBS

• This recommendation is based on limited indirect evidence and evidence from epidemiological studies.
• Evidence suggests that regular physical activity can improve gastric emptying and colon transit time, however, CKS found no direct evidence on the effect of regular physical activity on symptoms of people with irritable bowel syndrome.
• Evidence regarding the association between physical activity and IBS in the general population is inconclusive.
• The GDG also took into account the NICE public health intervention guidance [NICE, 2006] and the Chief Medical Officer's report on physical activity [DH, 2004].
• There is evidence that a programme of physical activity reduces the percentage of hard and incomplete stools in constipated people without IBS.

Basis for considering the use of probiotics

• Probiotics are microbial food supplements which, when administered in adequate amounts, have a beneficial effect on the host.
• These recommendations are based on evidence from 13 RCTs. However, 11 of these studies included fewer than 100 people, the majority were undertaken in secondary care, and there was significant heterogeneity between the studies.
• The consensus of the GDG was that [National Collaborating Centre for Nursing and Supportive Care, 2008]:
• Probiotics were not harmful, were widely available, and may benefit some people with IBS as part of their diet.
• Although there is some evidence from single trials, it was not sufficient to recommend named bacteria or probiotic products.

• Use single drugs or a combination of drugs, according to the predominant symptoms of the individual.
• Consider an antispasmodic, alongside dietary and lifestyle advice, for all people with irritable bowel syndrome, and in particular those with pain occurring as spasm.
• For people with constipation, consider treatment with a laxative.
• Bulk-forming laxatives are preferred (e.g. ispaghula or sterculia).
• For people who cannot tolerate a bulk-forming laxative, or who need an additional laxative, offer a macrogol (polyethylene glycol) or a stimulant laxative (for short-term use only).
• Lactulose is not recommended.
• For people with diarrhoea, consider treatment with an antimotility drug.
• Loperamide is the antimotility drug of choice.
• Advise people to adjust the dose of laxative or antimotility drug according to response. The aim is to produce a soft, well-formed stool.
• If symptoms do not respond to first-line treatment, consider a trial of a low dose tricyclic antidepressant (for pain relief).
• Start treatment at a low dose (equivalent to 5–10 mg amitriptyline at night).
• Review 4 weeks after starting treatment and titrate the dose up if necessary (the usual maximum dose is equivalent to 30 mg amitriptyline at night).
• Continue to review every 6–12 months.
• Consider a selective serotonin reuptake inhibitor if a tricyclic antidepressant has previously been shown to be ineffective.

• Tricyclic antidepressants and selective serotonin reuptake inhibitors are primarily used for the treatment of depression, and are only recommended here for their analgesic effect.

The evidence base on drug treatments in the management of irritable bowel syndrome (IBS) is generally poor. There is a high placebo response to treatment in people with IBS, but this often wears off after initial success. In general, controlled studies are poor showing only moderate responses, and there is a significant risk of positive publication bias as indicated by heterogeneity of trial results.

• These recommendations are consistent with the National Institute for Health and Clinical Excellence guidance Irritable bowel syndrome in adults [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].

Basis for recommending antispasmodics

• The Guideline Development Group (GDG) consensus was that antispasmodics should be used as first-line therapy alongside dietary and lifestyle advice for people with IBS, particularly those with pain occurring as spasm.
• Evidence from generally small, heterogeneous studies suggests that antispasmodics improve symptoms of pain, bloating, and bowel habits compared with placebo.
• There does not appear to be a difference in efficacy between antimuscarinics and smooth muscle relaxants, but there is an increase in adverse effects with antimuscarinics compared with smooth muscle relaxants.

Basis for recommending laxatives for constipation in IBS

• Evidence from nine RCTs suggests that fibre is more effective than placebo at improving global symptoms of IBS. Subgroup analysis suggests that soluble fibre is more effective than insoluble fibre. Direct evidence from two RCTs suggests that soluble fibre is more effective than insoluble fibre at improving global symptoms of IBS.
• There is good evidence that laxatives are clinically effective in the management of constipation in IBS. Much of this is indirect evidence from people defined as having simple constipation. However, the GDG considered that many of the participants had IBS, and that the evidence could be extrapolated.
• There was consensus among members of the GDG that IBS is more complex than simple constipation, and that some laxatives (e.g. lactulose) exacerbate the symptoms of IBS and should be avoided by people with IBS.

Basis for recommending loperamide for diarrhoea in IBS

• There is evidence from one study (n = 107) that antimotility drugs (loperamide and co-phenotrope) are effective for the short-term symptomatic relief of diarrhoea in IBS.
• There is some evidence that loperamide is more effective than co-phenotrope.
• There is a limited amount of evidence that loperamide improves global symptoms, pain, and bowel habit in the longer term.
• The GDG also noted that loperamide is widely used and accepted as clinically effective for the treatment of diarrhoea in people with IBS.

Basis for considering a tricyclic antidepressant (TCA) or a selective serotonin reuptake inhibitor (SSRI)

• There is good evidence from six RCTs (n = 434) mainly in people with refractory IBS, showing a significant global improvement in symptoms for both TCAs and SSRIs.
• There is limited evidence from several small studies showing:
• A significant reduction in pain for TCAs compared with placebo.
• A borderline improvement in bowel habit for TCAs compared with placebo.
• There is limited evidence from several small studies showing:
• A significant reduction in pain for SSRIs compared with placebo.
• A borderline improvement in bowel habit for SSRIs compared with placebo.
• No significant difference in bloating for SSRIs compared with placebo.

• Consider referral for psychological interventions for people who do not respond to diet, lifestyle, and drug treatments after 12 months.
• Cognitive behavioural therapy, hypnotherapy, and/or psychological therapy is recommended.

Basis for psychological interventions

• This recommendation is from the National Institute for Health and Clinical Excellence (NICE) guidance Irritable bowel syndrome in adults [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].
• There is some evidence in people with long term irritable bowel syndrome (IBS) of a significant global improvement in symptoms after 12 weeks and after 15 months, for dynamic psychotherapy plus medical therapy compared with medical therapy alone. Compared with 'usual treatment', psychotherapy improved global symptoms after 12 weeks, but this improvement was not maintained in the longer term (52 weeks); there was no difference in pain score at 12 weeks, nor at 52 weeks.
• There is good evidence, mainly in people with psychiatric comorbidities and refractory IBS, of a significant global improvement in symptoms for cognitive behavioural therapy (CBT) compared with no treatment or symptom monitoring. Evidence did not suggest an improvement in individual symptoms with CBT.
• Evidence on hypnotherapy in the management of irritable bowel syndrome (IBS) is generally poor, making it difficult to draw any conclusions about the efficacy of hypnotherapy for IBS.

• Refer to secondary care anyone who presents with a red flag indicator (see Differential diagnosis).
• Urgently refer:
• Anyone 40 years of age and older, reporting rectal bleeding with a change of bowel habit towards looser stools and/or increased stool frequency persisting for 6 weeks or more.
• Anyone 60 years of age and older, with rectal bleeding persisting for 6 weeks or more without a change in bowel habit and without anal symptoms.
• Anyone 60 years of age and older, with a change in bowel habit to looser stools and/or more frequent stools persisting for 6 weeks or more without rectal bleeding.
• Anyone presenting with a right lower abdominal mass consistent with involvement of the large bowel, irrespective of age.
• Anyone presenting with a palpable rectal mass (intraluminal and not pelvic), irrespective of age. (A pelvic mass outside the bowel warrants an urgent referral to a urologist or gynaecologist.)
• Men of any age with unexplained iron deficiency anaemia and haemoglobin of 11 g/100 mL or less.
• Non-menstruating women with unexplained iron deficiency anaemia and haemoglobin of 10 g/100 mL or less.
• Refer to a registered dietitian for advice and treatment (including single food avoidance and exclusion diets) if general lifestyle and dietary advice are insufficient by themselves to improve symptoms. Such advice should only be given by a registered dietitian.
• Consider referral for psychological interventions (cognitive behavioural therapy, hypnotherapy, or psychological therapy) for people who do not respond to diet, lifestyle, and drug treatments after 12 months.
• Consider referral if there is uncertainty abut the diagnosis.
• Consider referral if the person has health-related anxieties that have not been allayed.

Basis for referral of people with red flag indicators

• Recommendations for referral of people with red flag indicators are from the National Institute of Health and Clinical Excellence (NICE) guideline Irritable bowel syndrome in adults [NICE, 2008] and the NICE Referral guidelines for suspected cancer [NICE, 2005b].

Basis for referral if there is uncertainty about the diagnosis

• The British Society of Gastroenterology guidelines for the management of irritable bowel syndrome recommend referral if there is genuine uncertainty about the diagnosis [Spiller et al, 2007].

Basis for referral to a registered dietitian

• This recommendation is from the NICE guidance Irritable bowel syndrome in adults [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].
• Although there is some evidence to support the use of exclusion diets, the Guideline Development Group (GDG) believed that such diets should only be undertaken with the specialist help of a dietitian to ensure that the diet remains well balanced.

Basis for referral if there is health-related anxiety

• The British Society of Gastroenterology guidelines for the management of irritable bowel syndrome recommend referral if the person has concerns that have not been successfully allayed by consultation with their primary healthcare professional [Spiller et al, 2007].

Basis for referral for psychological interventions

• This recommendation is from the NICE guidance Irritable bowel syndrome in adults [National Collaborating Centre for Nursing and Supportive Care, 2008; NICE, 2008].
• There is some evidence in people with long term irritable bowel syndrome (IBS) of a significant global improvement in symptoms after 12 weeks and after 15 months, for dynamic psychotherapy plus medical therapy compared with medical therapy alone. Compared with 'usual treatment', psychotherapy improved global symptoms after 12 weeks, but this improvement was not maintained in the longer term (52 weeks); there was no difference in pain score at 12 weeks, nor at 52 weeks.
• There is good evidence, mainly in people with psychiatric comorbidities and refractory IBS, of a significant global improvement in symptoms for cognitive behavioural therapy (CBT) compared with no treatment or symptom monitoring. Evidence did not suggest an improvement in individual symptoms with CBT.
• Evidence on hypnotherapy in the management of irritable bowel syndrome (IBS) is generally poor, making it difficult to draw any conclusions about the efficacy of hypnotherapy for IBS.

• The use of aloe vera is not recommended for the treatment of irritable bowel syndrome (IBS).
• The use of acupuncture or reflexology should not be encouraged for the treatment of IBS.
• There are too many uncertainties regarding type and dose of herbal medicines to make a recommendation for practice.
• CKS advises that the use of herbal medicines should not be encouraged in people with IBS.
• There is insufficient evidence to make a recommendation on prebiotics.

Basis for not recommending aloe vera

• There is evidence from one study that aloe vera has no significant effect on the global or individual symptoms of irritable bowel syndrome (IBS) or on quality of life, compared with placebo.
• There is limited evidence of adverse effects associated with oral aloe preparations.

Basis for not encouraging acupuncture or reflexology

• Very limited evidence from one small study in 34 people suggests that reflexology has no effect on pain, bowel function, or bloating in people with IBS.
• There is some evidence from several small studies that shows no significant effect of acupuncture on IBS global symptoms, pain, or quality of life.
• There is evidence of potentially serious adverse effects (e.g. pneumothorax) associated with acupuncture.

Basis for herbal medicines

• Good quality evidence on the use of herbal medicines is limited and inconsistent. The available evidence generally shows no significant effect of herbal medicines on symptoms of IBS.
• CKS does not recommend the use of herbal preparations as these preparations are unlicensed and unregulated. The quality and safety of these preparations cannot therefore be guaranteed.

Basis for prebiotics

• Prebiotics are non-digestible food ingredients that affect the host by selectively targeting growth and/or activity of one or more species of bacteria in the colon.
• These recommendations are based on the consensus of the Guideline Development Group (GDG) [National Collaborating Centre for Nursing and Supportive Care, 2008].
• The GDG felt that there was only a moderate amount of weak evidence that showed no significant difference with regard to global symptoms or bloating between people given a prebiotic and people given a placebo.
• The GDG agreed that there was insufficient evidence to make a recommendation on prebiotics.