Psychological interventions, antidepressants, and positive diagnosis represent a novel approach to management and care of irritable bowel syndrome, says Dr James Dalrymple

Irritable bowel syndrome (IBS) is a condition frequently encountered by the primary care physician. Most commonly affecting people between the ages of 20 and 30 years, it is twice as common in women as in men.1,2 In the general population prevalence is estimated to be between 10% and 20%. Recent trends indicate that the prevalence of IBS is also significant in older people and should, therefore, be considered as a possible diagnosis in this category of patients presenting with unexplained abdominal symptoms.1,2

As indicated by online data from NHS Direct, the actual prevalence of IBS in the whole population may be higher than these estimates. It suggests that 75% of people consulting their online service with symptoms of IBS do not seek medical advice but rely on self-care.2 Based on the NHS Direct data, the extrapolated number of people in England and Wales consulting for IBS is between 1.6 and 3.9 million. The evidence does not suggest that age and race have any consistent effect on the incidence of symptoms.2

Signs and symptoms

Irritable bowel syndrome is a chronic, relapsing condition of unknown aetiology, which often affects patients for their entire life. It is characterised by the presence of abdominal pain/discomfort, which is relieved by defaecation, and changed bowel habit, often with disordered defaecation (altered frequency or stool form).1,2 In order to make a positive diagnosis of IBS at least two of the following signs should accompany these symptoms:1

  • straining, urgency, incomplete stool evacuation
  • abdominal bloating (more frequent in women) or distension, tension or hardness
  • eating makes symptoms worse
  • passage of mucus.

Associated non-colonic features include functional urinary and gynaecological problems, back pain, headaches, and psychological symptoms.4 These non-colonic features often result in inappropriate referral and investigations and delays in treatment.

The management of IBS focuses on the relief of symptoms and implies a long-term therapeutic alliance between the patient and the primary care physician, prompting shared care decision-making.2

The symptom profile of this condition varies and may require a combination of different modalities to achieve effective relief. These include diet and lifestyle interventions, patient education and self-help, pharmacological interventions, and behavioural and psychological therapies. No single drug will alleviate the multiple symptoms often seen in people with IBS. A combination of medicines and other therapeutic interventions should be used, focusing on the predominant symptom(s).2

About the guideline

The recent guideline from NICE on Irritable bowel syndrome in adults1,2 makes a number of recommendations. The guideline development group (GDG) identified 10 key priorities for implementation for the management of patients with IBS.1,2 These included the initial assessment, diagnostic tests, dietary and lifestyle advice, and pharmacological therapy.

The guideline emphasises the approach to positive diagnostic criteria, and the determination of optimal clinical and cost-effective management and therapies for IBS. It also stresses the importance of patient empowerment in terms of self-help for their condition and self-management of their medicines.


The aim of the guideline was to produce positive, pragmatic, diagnostic criteria for patients presenting with IBS.1 This would serve three main purposes by:

  • increasing patient confidence through positive diagnosis
  • increasing clinician confidence
  • providing potential for considerable NHS disinvestment by avoiding unnecessary investigations and referrals to multiple specialities.

The diagnostic criteria for a positive diagnosis of IBS were derived by the GDG from existing diagnostic tools. Any recommendations for the use of diagnostic criteria should ensure ease of use for GPs, who are responsible for the majority of the treatment of patients with IBS. Existing criterion-referenced diagnostic tools (ROME I to III, Manning, and Kruis) have been used in research, however, their use for everyday diagnosis has proved difficult.1

In order to provide a positive diagnosis of IBS, alternative diagnoses need to be excluded. The guideline recommends the following tests should be performed in those meeting criteria for IBS diagnosis to exclude differential diagnoses:1

  • full blood count (FBC)
  • erythrocyte sedimentation rate (ESR) or plasma viscosity
  • C-reactive protein (CRP)
  • endomysial antibody testing or tissue transglutaminase for coeliac disease.

The guideline found that the probability of organic disorders, including colon cancer, inflammatory bowel disease, thyroid disease, and lactose malabsorption was no different in patients with IBS compared to the general population, so tests to exclude these conditions are unnecessary. However, coeliac disease appears to occur more frequently in people with IBS.1 The guideline recommends that patients meeting the criteria for IBS should therefore not undergo additional investigations such as ultrasound, endoscopy, and thyroid function tests, which are not necessary to confirm a diagnosis of IBS.

The clear message from the guideline is that with a careful history and physical examination, positive diagnosis of IBS is possible. This, augmented by simple laboratory investigations (FBC, ESR, and CRP) to rule out more serious underlying pathology and the absence of red flag symptoms, makes the positive diagnosis of IBS robust. The presence of any red flag signs or symptoms is inconsistent with a diagnosis of IBS and prompt referral is indicated.5 These include:1

  • weight loss that is unexplained and unintentional
  • rectal bleeding
  • familial history of bowel or ovarian cancer
  • changed bowel habit (looser and/or more frequent stools) lasting for longer than 6 weeks in patients over 60 years of age.

Diet and lifestyle

As with many conditions affecting the gastrointestinal tract, diet and lifestyle may be factors that trigger or exacerbate symptoms of IBS. As well as providing general lifestyle advice, specific dietary advice should include a review of the diet and nutrition of patients with IBS. Patients should be advised to:1

  • take regular meals, without long gaps between them, and take time over eating—patients should not miss meals
  • take sufficient drinks during the day—at least eight cups of water or non-caffeinated fluids such as herbal teas, but less tea, coffee, alcohol, and carbonated drinks
  • reduce consumption of high-fibre foods, such as high-fibre breads and flour, cereals with high amounts of bran, whole grains like brown rice
  • eat less of foods containing ‘resistant starch’, which is still intact when it reaches the colon
  • limit daily fresh fruit intake to three 80 g portions per day
  • avoid sorbitol (found in sugar-free sweets, gum and drinks, and also in some diabetic and slimming products) if suffering with diarrhoea
  • eat oats (e.g. cereal, porridge) or linseed (up to one tablespoon daily) if affected by wind or bloating.


It was clear from the evidence that many people with IBS have excess fibre in their diet. The GDG agreed that the practice of recommending high fibre diets to people with IBS should cease and that the preferred daily fibre intake should be about 12 g per day rather than 24 g per day.2 In addition, the fibre should be in the soluble form, preferably from food rich in dietary fibre. Practitioners should review the type and amount of fibre in the patient’s diet.


Although there was no convincing evidence for the use of probiotics in IBS, this reflected the paucity of studies relevant to the process of guideline development. Patients who wish to take probiotics should be advised to take them for 4 weeks while monitoring any effect. The dose recommended by the manufacturer should be followed.

Exclusion diets

Food intolerance is often muted as an aetiological factor in IBS but there are no objective tests available to identify this. There are also few tests to confirm that food allergy is a factor in IBS. Data from dietary elimination and food challenge studies are not definitive.2 If diet is considered to be a major factor in a person’s symptoms, and general lifestyle and dietary advice has been followed, referral to a dietitian could be considered for advice on single food avoidance and an exclusion diet.1,2

Therapeutic interventions

The drug management strategy for patients with IBS should be based on the nature and severity of the symptoms, using individual medicines or combinations directed at the predominant symptom(s). There is good quality evidence showing significant improvement with antispasmodics when compared with placebo.2 Laxatives should be considered for the treatment of constipation as they have been shown to be effective and there is only limited evidence that they are associated with adverse gastrointestinal effects. Patients with IBS should be advised to adjust the dose of their medicine to achieve stool formation corresponding to Bristol Stool Form Scale type 4.1,2,6 The use of lactulose by patients with IBS should be discouraged as it has been shown to increase the risk of abdominal symptoms.

Loperamide should be considered as the first-line treatment for diarrhoea and in some circumstances the daily dose might need to exceed 16 mg to be effective. This dose currently exceeds the licenced dose, so informed consent should be obtained from the patient and documented.1,2

The evidence in the guideline for the use of antidepressants for their analgesic effect supports the use of tricyclic antidepressants (TCAs) for patients with refractory IBS. The guideline recommends that TCAs are considered as a second-line treatment, starting at a low dose (i.e. 5–10 mg equivalent of amitriptyline) to be taken once at night. The treatment should be reviewed regularly. It may be increased to a maximum dose not exceeding 30 mg equivalent dose of amitriptyline. Selective serotonin reuptake inhibitors (SSRIs) at a low dose may be tried if TCAs have no effect. It should be borne in mind that treatment with TCAs and SSRIs for this purpose is not currently covered by their licensed uses and informed consent should be obtained and documented.1

Psychological interventions

Although it has been shown that there are no greater psychological disturbances in people with IBS than in the general population, anxiety and depression can be major factors in the symptom profiles of IBS.2 Psychotherapy has been suggested as a possible treatment to reduce pain and symptoms and also to improve quality of life. This includes cognitive behavioural therapy, hypnotherapy, and psychological therapy. The guideline recommends that one or a combination of these should be considered for people who have had IBS for at least 12 months and who have not responded to first-line therapies.

Complementary therapies

A number of complementary and alternative therapies were considered by the GDG. The guideline says the use of aloe vera should be discouraged based on the available evidence. Reflexology and acupuncture are not effective in IBS and their use should not be encouraged in these patients.1


The guideline from NICE on Irritable bowel syndrome in adults gives clear advice on the diagnosis and management of IBS. The concepts of forming a positive diagnosis, reducing dietary fibre, using antidepressants, and the use of psychological interventions represent a novel approach for some health professionals. However, it is hoped that the guideline will result in effective treatment of IBS without the need for unnecessary investigations and referral.

NICE implementation tools

NICE has developed the following tools to support implementation of its guideline on the diagnosis and management of irritable bowel syndrome. They are now available to download from the NICE website:

Implementation advice

The implementation advice document contains suggested actions for implementing the guideline. It aims to help implementers identify recommendations in the guideline that are not part of current practice, and should be used alongside the costing report and template.

Costing tools

National cost reports and local cost templates for the guideline have also been produced:

Costing reports are estimates of the national cost impact arising from implementation based on assumptions about current practice, and predictions of how it might change following implementation of the guideline.

Costing templates are spreadsheets that allow individual NHS organisations and local health economies to estimate the costs of implementation taking into account local variation from the national estimates, and they quickly assess the impact the guideline may have on local budgets.

Slide set

The slides are aimed at supporting organisations to raise awareness of the guideline at a local level and can be edited to cater for local audiences. They do not cover all the recommendations from the guideline but contain key messages, and should be used in conjunction with the Quick Reference Guide.

  • IBS is a very common disorder and a common source of gastroenterological referral
  • The IBS guideline, if followed, could significantly reduce referrals to secondary care and the costs involved
  • Referrals to gastroenterology could be screened against this guideline by GPwSIs or clinical assessment and treatment services
  • Local community treatment services for IBS could be commissioned from referral cost savings to include dietetics, lifestyle advice, and psychological therapies
  • Recommended pharmacological therapies have mainly low acquisition costs—local formularies could list these
  • Tariff prices:a
      • gastroenterology outpatient = £168 (new); £80 (follow up)
      • flexible sigmoidoscopy = £325
  1. National Institute for Health and Care Excellence. Irritable bowel syndrome in adults. Diagnosis and management of irritable bowel syndrome in primary care. Clinical Guideline 61. London: NICE, 2008.
  2. National Collaborating Centre for Nursing and Supportive Care. Diagnosis and management of irritable bowel syndrome in primary care. London: NICE, 2008.
  3. Wilson S, Roberts L, Roalfe A et al. Prevalence of irritable bowel syndrome: a community survey. Br J Gen Pract 2004; 54 (504): 495–502.
  4. Whorwell P, McCallum M, Creed F, Roberts C. Non-colonic features of irritable bowel syndrome. Gut 1986; 27 (1): 37–40.
  5. National Institute for Health and Care Excellence. Referral guidelines for suspected cancer. Clinical Guideline 27.London: NICE, 2005.
  6. Heaton K, Radvan J, Cripps H. Defecation frequency and timing, and stool form in the general population: a prospective study. Gut 1992; 33 (6): 818–824.G