Homeopathy for treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common, chronic disorder that leads to decreased health-related quality of life and work productivity. Evidence-based treatment guidelines have not been able to give guidance on the effects of homeopathic treatment for IBS because no systematic reviews have been carried out to assess the effectiveness of homeopathic treatment for IBS. Two types of homeopathic treatment were evaluated in this systematic review. In clinical homeopathy a specific remedy is prescribed for a specific condition. This differs from individualised homeopathic treatment, where a homeopathic remedy based on a person's individual symptoms is prescribed after a detailed consultation.

To assess the effectiveness and safety of homeopathic treatment for treating IBS.

We searched MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), Cochrane IBD/FBD Group Specialised Register, Cochrane Complementary Medicine Field Specialised Register and the database of the Homeopathic Library (Hom-inform) from inception to February 2013.

Randomised controlled trials (RCTs), cohort and case-control studies that compared homeopathic treatment with placebo, other control treatments, or usual care, in adults with IBS were considered for inclusion.

Two authors independently assessed the risk of bias and extracted data. The primary outcome was global improvement in IBS. The overall quality of the evidence supporting this outcome was assessed using the GRADE criteria. We calculated the mean difference (MD) and 95% confidence interval (CI) for continuous outcomes and the risk ratio (RR) and 95% CI for dichotomous outcomes.

Three RCTs (213 participants) were included. No cohort or case-control studies were identified. Two studies published in 1976 and 1979 compared clinical homeopathy (homeopathic remedy) to placebo for constipation-predominant IBS. One study published in 1990 compared individualised homeopathic treatment (consultation plus remedy) to usual care (defined as high doses of dicyclomine hydrochloride, faecal bulking agents and diet sheets asking the patient to take a high fibre diet) for the treatment of IBS in female patients. Due to the low quality of reporting in the included studies the risk of bias in all three studies was unclear on most criteria and high for some criteria. A meta-analysis of two small studies (129 participants with constipation-predominant IBS) found a statistically significant difference in global improvement between the homeopathic remedy asafoetida and placebo at a short-term follow-up of two weeks. Seventy-three per cent of patients in the homeopathy group improved compared to 45% of placebo patients (RR 1.61, 95% CI 1.18 to 2.18). There was no statistically significant difference in global improvement between the homeopathic remedies asafoetida plus nux vomica and placebo. Sixty-eight per cent of patients in the homeopathy group improved compared to 52% of placebo patients (1 study, N = 42, RR 1.31, 95% CI 0.80 to 2.15). GRADE analyses rated the overall quality of the evidence for the outcome global improvement as very low due to high or unknown risk of bias, short-term follow-up and sparse data. There was no statistically significant difference found between individualised homeopathic treatment and usual care (1 RCT, N = 20) for the outcome "feeling unwell", where the participant scored how "unwell" they felt before, and after treatment (MD 0.03; 95% CI -3.16 to 3.22). None of the included studies reported on adverse events.

A pooled analysis of two small studies suggests a possible benefit for clinical homeopathy, using the remedy asafoetida, over placebo for people with constipation-predominant IBS. These results should be interpreted with caution due to the low quality of reporting in these trials, high or unknown risk of bias, short-term follow-up, and sparse data. One small study found no statistically difference between individualised homeopathy and usual care (defined as high doses of dicyclomine hydrochloride, faecal bulking agents and diet sheets advising a high fibre diet). No conclusions can be drawn from this study due to the low number of participants and the high risk of bias in this trial. In addition, it is likely that usual care has changed since this trial was conducted. Further high quality, adequately powered RCTs are required to assess the efficacy and safety of clinical and individualised homeopathy compared to placebo or usual care.