The prevalence of irritable bowel syndrome (IBS) varies depending on the criteria used to diagnose it, but it ranges from about 5% to 20%. IBS is associated with abnormal gastrointestinal motor function and enhanced visceral perception, as well as psychosocial and genetic factors. People with IBS often have other bodily and psychiatric symptoms, and have an increased likelihood of having unnecessary surgery compared with people without IBS.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in people with IBS? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found 27 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: 5HT3 receptor antagonists (alosetron and ramosetron), 5HT4 receptor agonists (tegaserod), antidepressants (tricyclic antidepressants and selective serotonin reuptake inhibitors [SSRIs]), antispasmodics (including peppermint oil), cognitive behavioural therapy (CBT), hypnotherapy, loperamide, and soluble and insoluble fibre supplementation.
The key features of irritable bowel syndrome (IBS) are chronic, recurrent abdominal pain or discomfort, associated with disturbed bowel habit, in the absence of any structural abnormality to account for these symptoms.
The prevalence of IBS varies depending on the criteria used to diagnose it, but it ranges from about 5% to 20%.IBS is associated with abnormal GI motor function, enhanced visceral perception, abnormalities in central pain processing, and altered gut flora, as well as psychosocial and genetic factors.People with IBS often have other bodily and psychiatric symptoms, and have an increased likelihood of having unnecessary surgery compared with people without IBS.A positive symptom-based diagnosis and a graded general treatment approach are cornerstones in the management of people with IBS.
Antidepressants (tricyclic antidepressants and SSRIs) may reduce global symptoms of IBS and abdominal pain compared with placebo.
Antispasmodics (including peppermint oil) may reduce global symptoms of IBS and abdominal pain compared with placebo.
We don't know whether soluble fibre supplementation (ispaghula) is more effective than placebo at improving global symptoms or abdominal pain in IBS as the data are contradictory.
Insoluble fibre supplementation does not reduce global symptoms of IBS or abdominal pain compared with placebo, but we found no evidence from RCTs to support the observation reported by some investigators that it in fact exacerbates symptoms.
The 5HT4 receptor agonist tegaserod reduces global symptoms of IBS and abdominal pain compared with placebo in people with constipation-predominant IBS.
CAUTION: Tegaserod may be associated with cerebrovascular and cardiovascular ischaemic events.
5HT3 receptor agonists (alosetron and ramosetron) reduce global symptoms of IBS and abdominal pain compared with placebo.
Alosetron reduces global symptoms of IBS and abdominal pain in diarrhoea-predominant IBS compared with placebo in women, but we don't know whether it is effective in men, or whether this effect applies to those with IBS with an alternating bowel habit.Alosetron may be more effective than mebeverine at reducing symptoms in women with diarrhoea-predominant IBS, but we don't know whether it is effective in men.CAUTION: Alosetron may be associated with severe constipation and ischaemic colitis.Ramosetron may reduce global symptoms of IBS and abdominal pain, and improve abnormal bowel habits, compared with placebo in people with diarrhoea-predominant IBS.
CBT may reduce IBS symptoms compared with control therapy or physician's usual care in the short term. We don't know whether it is beneficial in the longer term.
Hypnotherapy may reduce IBS symptoms compared with control therapy or physician's usual care in the short term.
Loperamide may reduce stool frequency in diarrhoea-predominant IBS, but it may not improve other symptoms compared with placebo.