Peppermint oil is the most effective treatment for irritable bowel syndrome (IBS), finds research published on bmj.com today.
The findings prompt the authors to call for a revamp of national guidelines on the management of IBS in light of this new evidence.
IBS affects between 5% and 20% of the population, but is notoriously difficult to treat, with probiotics, antidepressants, hypnotherapy and laxatives all considered to have a role in easing symptoms.
Recently published NICE guidelines on the management of IBS advocate the use of complementary medicine in the absence of any effective drugs.
The evidence for the effectiveness of fibre, antispasmodics and peppermint oil, which are also prescribed, has been unclear, say the authors.
They therefore carried out a systematic review and meta-analysis of published data, involving more than 2,500 patients with IBS.
The researchers analysed 12 studies comparing fibre with placebo or no treatment and involving 591 patients. Only isphaghula husk (soluble fibre) significantly reduced symptoms.
They identified 22 studies comparing various antispasmodics with placebo in 1,778 patients. Hyoscine, extracted from the cork wood tree, was the most effective, and should be used as the firstline antispasmodic therapy in primary care.
But peppermint oil seemed to be the most effective treatment of the three, based on four trials involving 392 patients.
The number needed to treat IBS symptoms in one patient was 11 for fibre, 5 for antispasmodics, and 2.5 for peppermint oil. None of the treatments had serious adverse effects.
These treatments have been overlooked because of the introduction of newer more expensive drugs which were withdrawn due to lack of efficacy and safety concerns, say the authors.
The results of this study should “reawaken interest in the pharmacotherapy of irritable bowel syndrome and stimulate further research,” says Professor Roger Jones from King’s College London, in an accompanying editorial.
But he is cautions that this new evidence must not detract from the need to take a holistic approach to diagnosis and treatment of IBS, to include the physical, psychological, and social factors involved.
BMJ 2008;337: a2313 (paper)
bmj.com 2008; doi 10.1136/bmj.a2213 (editorial)