1.1.1. Initial assessment

1.1.1.1.

Healthcare professionals should consider assessment for IBS if the person reports having had any of the following symptoms for at least 6 months:

• Abdominal pain or discomfort
• Bloating
• Change in bowel habit. [2008]

1.1.1.2.

All people presenting with possible IBS symptoms should be assessed and clinically examined for the following ‘red flag’ indicators and should be referred to secondary care for further investigation if any are present:

• signs and symptoms of cancer in line with the NICE guidance on recognition and referral for suspected cancer
• inflammatory markers for inflammatory bowel disease [2017].

1.1.1.3.

This recommendation has been withdrawn [2017].

1.1.1.4.

Adiagnosis of IBS should be considered only if the person has abdominal pain or discomfort that is either relieved by defaecation or 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 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. [2008]

1.1.2. Diagnostic tests

1.1.2.1.

In people who meet the IBS diagnostic criteria, the following tests should be undertaken to exclude other diagnoses:

• full blood count (FBC)
• erythrocyte sedimentation rate (ESR) or plasma viscosity
• c-reactive protein (CRP)
• antibody testing for coeliac disease (endomysial antibodies [EMA] or tissue transglutaminase [TTG]). [2008]

1.1.2.2.

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

• ultrasound
• rigid/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). [2008]

1.2.1. Dietary and lifestyle advice

1.2.1.1.

People with IBS should be given information that explains the importance of self-help in effectively managing their IBS. This should include information on general lifestyle, physical activity, diet and symptom-targeted medication. [2008]

1.2.1.2.

Healthcare professionals should encourage people with IBS to identify and make the most of their available leisure time and to create relaxation time. [2008]

1.2.1.3.

Healthcare professionals should assess the physical activity levels of people with IBS, ideally using the General Practice Physical Activity Questionnaire (GPPAQ; see appendix J of the full guideline). People with low activity levels should be given brief advice and counselling to encourage them to increase their activity levels. [2008]

1.2.1.4.

Diet and nutrition should be assessed for people with IBS and the following general advice given.

• Have regular meals and take time to eat.
• Avoid missing meals or leaving long gaps between eating.
• Drink at least 8 cups of fluid per day, especially water or other non-caffeinated drinks, for example herbal teas.
• Restrict tea and coffee to 3 cups per 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 whole grains 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 3 portions per day (a portion should be approximately 80 g).
• 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 1 tablespoon per day). [2008]

1.2.1.5.

Healthcare professionals should review the fibre intake of people with IBS, adjusting (usually reducing) it while monitoring the effect on symptoms. People with IBS should be discouraged from eating insoluble fibre (for example, bran). If an increase in dietary fibre is advised, it should be soluble fibre such as ispaghula powder or foods high in soluble fibre (for example, oats). [2008]

1.2.1.6.

People with IBS who choose to try probiotics should be advised to take the product for at least 4 weeks while monitoring the effect. Probiotics should be taken at the dose recommended by the manufacturer. [2008]

1.2.1.7.

Healthcare professionals should discourage the use of aloe vera in the treatment of IBS. [2008]

1.2.1.8.

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 [fermentable oligosaccharides, disaccharides, monosaccharides and polyols] diet)
• only be given by a healthcare professional with expertise in dietary management. [new 2015]

1.2.2. 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 medication is determined by the predominant symptom(s).

1.2.2.1.

Healthcare professionals should consider prescribing antispasmodic agents for people with IBS. These should be taken as required, alongside dietary and lifestyle advice. [2008]

1.2.2.2.

Laxatives should be considered for the treatment of constipation in people with IBS, but people should be discouraged from taking lactulose. [2008]

1.2.2.3.

Consider linaclotide for people with IBS only if:

• optimal or maximum tolerated doses of previous laxatives from different classes have not helped and
• they have had constipation for at least 12 months.

Follow up people taking linaclotide after 3 months. [new 2015]

1.2.2.4.

Loperamide should be the first choice of antimotility agent for diarrhoea in people with IBS. [2008]

1.2.2.5.

People with IBS should be advised how to adjust their doses of laxative or antimotility agent according to the clinical response. The dose should be titrated according to stool consistency, with the aim of achieving a soft, well-formed stool (corresponding to Bristol Stool Form Scale type 4). [2008]

1.2.2.6.

Consider tricyclic antidepressants (TCAs) as second-line treatment for people with IBS if laxatives, loperamide or antispasmodics have not helped. Start treatment at a low dose (5–10 mg equivalent of amitriptyline), taken once at night, and review regularly. Increase the dose if needed, but not usually beyond 30 mg.^[2] [2015]

1.2.2.7.

Consider selective serotonin reuptake inhibitors (SSRIs) for people with IBS only if TCAs are ineffective.² [2015]

1.2.2.8.

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 4 weeks and then every 6–12 months.² [2015]

1.2.3. Psychological interventions

1.2.3.1.

Referral for psychological interventions (cognitive behavioural therapy [CBT], hypnotherapy and/or psychological therapy) should be considered for people with IBS who do not respond to pharmacological treatments after 12 months and who develop a continuing symptom profile (described as refractory IBS). [2008]

1.2.4. Complementary and alternative medicine (CAM)

1.2.4.1.

The use of acupuncture should not be encouraged for the treatment of IBS. [2008]

1.2.4.2.

The use of reflexology should not be encouraged for the treatment of IBS. [2008]

1.2.5. Follow-up

1.2.5.1.

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 and/or referral to secondary care. [2008]

Why this is important

Reviews have shown that TCAs and SSRIs have each been compared with placebo in the treatment of IBS, but not at low doses. In practice, TCAs are used at higher doses, and concordance with treatment is poor because of side effects. The Guideline Development Group clinicians believe that at low doses (5–10 mg equivalent of amitriptyline), TCAs could be the treatment of choice for IBS, but there is a lack of evidence to support this. A newer type of antidepressant, SNRIs, may also be useful in the treatment of IBS-associated pain. A large randomised trial is proposed, comparing an SSRI, a TCA and an SNRI with placebo. Participants should be adults with a positive diagnosis of IBS, stratified by type of IBS and randomised to treatments. The type of IBS is defined by the predominant bowel symptom: diarrhoea, constipation or alternating symptoms. The primary outcome should be global improvement in IBS symptoms. Health-related quality of life should also be measured, and adverse effects recorded. Study outcomes should be assessed 12, 26 and 52 weeks after the start of therapy.

Why this is important

Reviews show some evidence of effect when comparing psychological interventions with a control group, with the greatest effect shown in people who have refractory IBS. Many trials are small in size. Certain psychological interventions – namely, CBT, hypnotherapy and psychological therapy – are thought to be useful in helping people with IBS to cope with their symptoms, but it is unclear at what stage these should be given, including whether they should be used as first-line therapies in primary care. A large randomised trial is proposed, comparing CBT, hypnotherapy and psychological therapy (in particular, psychodynamic interpersonal therapy). Participants should be adults with a positive diagnosis of IBS, and they should be stratified into those with and without refractory IBS and then randomised to treatments. The primary outcome should be global improvement in IBS symptoms. Health-related quality of life should also be measured, and adverse effects recorded. Study outcomes should be assessed 12, 26 and 52 weeks after the start of therapy.

Why this is important

Most people with IBS experience symptoms that are relatively short-lived or that only trouble them on an intermittent basis. Some people, however, develop chronic and severe symptoms that are difficult to treat. There are relatively few prospective studies that have investigated this problem.

A large, prospective, population-based cohort study is proposed, which would evaluate people in the community with IBS symptoms according to measures of bowel symptomatology, physical symptom profile, psychological symptoms, childhood adversity, psychiatric history, social supports, quality of life and other relevant potential predictors. Participants would be re-evaluated 12 and 24 months later using similar measures. Baseline variables would be used to predict chronicity of symptoms, quality of life and healthcare utilisation at 12 and 24 months.

Why this is important

Reviews of biofeedback and relaxation therapies suggest a positive effect on the control of IBS symptoms, but evidence is limited and not sufficient to make recommendations. Patient representation in the Guideline Development Group supports this view, from a personal and anecdotal perspective.

Recent developments in computer-aided biofeedback methods merit investigation. A large randomised trial is proposed to compare relaxation therapy, computer-aided biofeedback therapy and attention control in primary care. Participants should be adults with a positive diagnosis of IBS, and they should be stratified into those with and without refractory IBS and then randomised to treatments. The primary outcome should be global improvement in IBS symptoms. Health-related quality of life should also be measured, and adverse effects recorded. Study outcomes should be assessed 12, 26 and 52 weeks after the start of therapy. Qualitative data should be generated relating to how people with IBS perceive their condition.

Why this is important

Reviews of herbal medicines suggest a positive effect on the control of IBS symptoms, but evidence is limited and not sufficient to make recommendations (8 comparisons from the 6 trials provide heterogeneous data, which are very difficult to interpret). A large randomised placebo-controlled trial is proposed, comparing Chinese and non-Chinese herbal medicines (both single and multiple compounds) that are available in the UK as standard preparations. Participants should be adults with a positive diagnosis of IBS, and they should be stratified by type of IBS and then randomised to treatments. The primary outcome should be global improvement in IBS symptoms, with symptom scores recorded using a validated scale. Health-related quality of life should also be measured, and adverse events recorded. Study outcomes should be assessed 12, 26 and 52 weeks post-intervention.

Interventions that must (or must not) be used

We usually use ‘must’ or ‘must not’ only if there is a legal duty to apply the recommendation. Occasionally we use ‘must’ (or ‘must not’) if the consequences of not following the recommendation could be extremely serious or potentially life threatening.

Interventions that should (or should not) be used – a ‘strong’ recommendation

We use ‘offer’ (and similar words such as ‘refer’ or ‘advise’) when we are confident that, for the vast majority of patients, an intervention will do more good than harm, and be cost effective. We use similar forms of words (for example, ‘Do not offer…’) when we are confident that an intervention will not be of benefit for most patients.

Interventions that could be used

We use ‘consider’ when we are confident that an intervention will do more good than harm for most patients, and be cost effective, but other options may be similarly cost effective. The choice of intervention, and whether or not to have the intervention at all, is more likely to depend on the patient’s values and preferences than for a strong recommendation, and so the healthcare professional should spend more time considering and discussing the options with the patient.

Recommendation wording in guideline updates

NICE began using this approach to denote the strength of recommendations in guidelines that started development after publication of the 2009 version of ‘The guidelines manual’ (January 2009). This does not apply to any recommendations ending [2008] (see ‘Update information’ above for details about how recommendations are labelled). In particular, for recommendations labelled [2008] the word ‘consider’ may not necessarily be used to denote the strength of the recommendation.