Irritable bowel syndrome in adults: diagnosis and management

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 mg to 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.