Homeopathy for treatment of irritable bowel syndrome: no good evidence for effectiveness

The aim of this update of a Cochrane review was to assess the effectiveness and safety of homeopathic treatment for irritable bowel syndrome (IBS). Hold on, the bit about safety is odd here and does not bode well: one cannot possibly assess the safety of an intervention on the basis of just a few trials.

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 as measured by an IBS symptom severity score. Secondary outcomes included quality of life, abdominal pain, stool frequency, stool consistency, and adverse events. The overall certainty of the evidence supporting the primary and secondary outcomes was assessed using the GRADE criteria. The Cochrane risk of bias tool was used to assess risk of bias.

Four RCTs (307 participants) were included. Two studies compared clinical homeopathy (homeopathic remedy, asafoetida or asafoetida plus nux vomica) to placebo for IBS with constipation (IBS-C). One study compared individualised homeopathic treatment (consultation plus remedy) to usual care for the treatment of IBS in female patients. One study was a three armed RCT comparing individualised homeopathic treatment to supportive listening or usual care.

The risk of bias in three studies (the two studies assessing clinical homeopathy and the study comparing individualised homeopathic treatment to usual care) was unclear on most criteria and high for selective reporting in one of the clinical homeopathy studies. The three armed study comparing individualised homeopathic treatment to usual care and supportive listening was at low risk of bias in four of the domains and high risk of bias in two (performance bias and detection bias).

A meta-analysis of the studies assessing clinical homeopathy, (171 participants with IBS-C) was conducted. At short-term follow-up of two weeks, global improvement in symptoms was experienced by 73% (46/63) of asafoetida participants compared to 45% (30/66) of placebo participants (RR 1.61, 95% CI 1.18 to 2.18; 2 studies, very low certainty evidence).

In the other clinical homeopathy study at two weeks, 68% (13/19) of those in the asafoetida plus nux vomica arm and 52% (12/23) of those in the placebo arm experienced a global improvement in symptoms (RR 1.31, 95% CI 0.80 to 2.15; very low certainty evidence).

In the study comparing individualised homeopathic treatment to usual care (N = 20), the mean global improvement score (feeling unwell) at 12 weeks was 1.44 + 4.55 (n = 9) in the individualised homeopathic treatment arm compared to 1.41 + 1.97 (n=11) in the usual care arm (MD 0.03; 95% CI -3.16 to 3.22; very low certainty evidence).In the study comparing individualised homeopathic treatment to usual care, the mean IBS symptom severity score at 6 months was 210.44 + 112.4 (n = 16) in the individualised homeopathic treatment arm compared to 237.3 + 110.22 (n = 60) in the usual care arm (MD -26.86, 95% CI -88.59 to 34.87; low certainty evidence).

The mean quality of life score (EQ-5D) at 6 months in homeopathy participants was 69.07 (SD 17.35) compared to 63.41 (SD 23.31) in usual care participants (MD 5.66, 95% CI -4.69 to 16.01; low certainty evidence). In the study comparing individualised homeopathic treatment to supportive listening, the mean IBS symptom severity score at 6 months was 210.44 + 112.4 (n = 16) in the individualised homeopathic treatment arm compared to 262 + 120.72 (n = 18) in the supportive listening arm (MD -51.56, 95% CI -129.94 to 26.82; very low certainty evidence). The mean quality of life score at 6 months in homeopathy participants was 69.07 (SD 17.35) compared to 63.09 (SD 24.38) in supportive listening participants (MD 5.98, 95% CI -8.13 to 20.09; very low certainty evidence). None of the included studies reported on abdominal pain, stool frequency, stool consistency, or adverse events.

The authors concluded that the results for the outcomes assessed in this review are uncertain. Thus no firm conclusions regarding the effectiveness and safety of homeopathy for the treatment of IBS can be drawn. Further high quality, adequately powered RCTs are required to assess the efficacy and safety of clinical and individualised homeopathy for IBS compared to placebo or usual care.

[The previous version of this review was published in 2013 and concluded: 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.]

This is a thorough review that is technically well-done (no wonder, as it had to comply with Cochrane standards!). However, as with some other Cochrane reviews of homeopathy, acupuncture and other SCAMs, one might object to the phraseology used in the conclusions (the part that most people would focus on). Don’t get me wrong, the conclusions are technically correct; however, they are not as clear as they should be and hide the essence of the evidence, in my view.

Systematic reviews have one main purpose: they need to inform the reader whether there is or is not good evidence that the treatment in question works for the condition in question. This question is not well addressed by stating THE RESULTS ARE UNCERTAIN. The truth is that a firm conclusion can very well be drawn: THERE IS NO GOOD EVIDENCE THAT ANY FORM OF HOMEOPATHY IS EFFECTIVE FOR IBS!

Surely that’s correct and firm enough!!!

Why do the authors not dare to put this clearly?

Probably because some of them are well-known, long-term proponents of homeopathy.

Why does the Cochrane Collaboration allow them to get away with their petty attempt of obfuscation?

Search me!