Guidelines for the management of irritable bowel syndrome (IBS) are long overdue. However, devising guidelines for a functional disorder such as IBS is a very daunting task.
In IBS there is no obvious end-point, and therefore clinical trials have been difficult to interpret. Even in well conducted trials there is a very strong placebo response, probably reflecting the greater contact between patients and healthcare professionals. Also, studies are almost exclusively from secondary care.
The working party of the British Society of Gastroenterology (BSG) took into account some 2521 relevant papers as well as reviews and representations from IBS patient groups and the IBS Network in drawing up their guidelines for the management of IBS.1 The result is a very comprehensive overview of the recognition of the syndrome, its aetiology and its management.
A significant milestone has been the recognition of the social impact of IBS. Despite the benign nature of the disorder, quality of life is considerably reduced, with more than 40% of patients reporting avoidance of activities including travel, work and socialising. In addition, difficulty in confirming the diagnosis may lead to further worry.
Although the aetiology is poorly understood, the report confirms that there is no consistent evidence of abnormal motility. On the other hand, patients do exhibit evidence of altered CNS processing of visceral pain consistent with hypersensitivity. It is recognised that some 10–20% of patients relate the onset of symptoms to an acute gastrointestinal illness. A parallel example would be post-herpetic neuropathy.
The guidelines emphasise the positive diagnosis in primary care without extensive investigation, and in most cases without referral to a hospital clinic.
The Manning, Rome I and Rome II criteria are acknowledged, but the diagnosis is based on a careful and detailed history based on several short interviews and observation over time. Consideration of which patients to refer include those with atypical symptoms or those who present for the first time in later life.
There are no recommendations for any specific investigation in primary care (see Figure 1, below). Personally, I feel that this is an oversight. A full blood count (FBC), ESR, faecal occult blood, and possibly thyroid function tests (TFTs), endomysial antibodies and a faecal sample can be (ost useful as baseline investigations.
|Figure 1: Stages in the evaluation of irritable bowel syndrome (IBS)*|
It is recommended that the management of IBS should be carried out mainly in primary care. The mainstay of such management is explanation and reassurance, adjustments to diet when appropriate, and identification of symptom triggers.
This is excellent advice, but many GPs are uncomfortable in attempting to explain a range of different symptoms. IBS patient groups often criticise GPs for dismissing the illness as something trivial.
In addition, explanations and advice can be very time consuming and do not fit comfortably into a 10-minute consultation. Clearly there is a need for better doctor education, but there is a strong argument for a specialist nurse practitioner in the education and support of patients.
In the treatment of IBS, the guidelines state that current available pharmacological treatments have a limited value. In studies, many medications for IBS do not achieve better symptom relief than placebos.
However, there are some helpful interventions and the recommendation depends to some extent on the type of IBS symptoms, which may be broadly divided into constipation-predominant IBS (C-IBS), diarrhoea-predominant (D-IBS) or mixed.
Antidepressants are currently the most effective drugs for treating IBS by modifying gut motility and by altering visceral nerve responses. In my own experience, low nocturnal doses of tricyclic antidepressants can certainly be of value. In D-IBS, loperamide or codeine may help to control symptoms.
Finally, the guidelines give appropriate space to the discussion of the use of psychological therapies – from simple behaviour therapy, relaxation therapy, hypnosis and biofeedback to cognitive behaviour therapy and dynamic psychotherapy. Although such therapies are highly effective, most GPs do not have ready access to them.
The management of IBS is summarised in the guidelines under the headings shown in Table 1, below.
|Table 1: Summary of management guide for irritable bowel syndrome|
The guidelines are due to be updated in 2–3 years' time. Much progress has been made in the research into IBS over the past decade and new therapies are being evaluated. The BSG guidelines are well worth reading and provide an excellent overview of IBS.
- Jones J, Boorman J, Cann P et al. British Society of Gastroenterology guidelines for the management of irritable bowel syndrome. Gut 2000; 47 (Suppl II): ii1-ii19.