Moxibustion in the management of irritable bowel syndrome: systematic review and meta-analysis

Irritable bowel syndrome (IBS) is one of the most common medical conditions related to the digestive system, affecting between 5 and 20% of the adult population worldwide. This chronic condition is characterized by abdominal pain or discomfort associated with changes in bowel habits, symptoms that persist for at least three months and significantly affect patient quality of life. In addition to physical and emotional suffering, IBS represents an important economic burden on health systems, since people with this condition use medical resources about 1.5 times more than the general population.

Despite its high prevalence, the exact cause of IBS is still not completely understood by medicine. It is known that factors such as alterations in intestinal motility, intestinal hypersensitivity, abnormal neurologic responses to stress, and imbalances in the normal intestinal flora contribute to the development of symptoms. Conventional treatment, which includes antispasmodic medications, fiber supplements, and antidepressants, offers only limited benefits, leading many patients to seek complementary and alternative therapies. In this context, researchers from South Korea conducted a systematic review and meta-analysis to critically evaluate the scientific evidence available on the use of moxibustion in the treatment of IBS.

The study carefully analyzed the world scientific literature in search of randomized controlled clinical trials that compared moxibustion with sham treatments (placebo), conventional medications, or other active therapies in patients with IBS. Moxibustion is a traditional Chinese therapeutic technique that uses heat generated by burning herbal preparations containing dried leaves of Artemisia vulgaris (艾, ài) over specific acupuncture points. This practice can be performed directly, applying heat directly over the skin, or indirectly, using insulating materials such as ginger, salt, or herbal preparations between the heat source and the skin. The researchers conducted comprehensive searches across major medical databases, including Medline, EMBASE, Cochrane Central Register, AMED, CINAHL, and Chinese databases, looking for studies published in English, Korean, and Chinese through August 2012.

The analysis included 20 randomized controlled clinical trials involving a total of 1,625 participants. Most studies (19 of 20) were conducted in China, with only one performed in the United States. Participants presented with different types of IBS: diarrhea-predominant (12 studies), constipation-predominant (2 studies), or unspecified type (6 studies). The diagnosis of IBS was based on recognized medical criteria, such as Rome II or III criteria, traditional Chinese medicine criteria, or a combination of these with investigations to exclude organic disease.

Moxibustion treatments varied considerably across studies: 8 tested moxibustion alone, 7 combined moxibustion with acupuncture, 2 combined moxibustion with conventional medications, 2 with Chinese herbal medicine, and 1 with psychotherapy. The treatment period ranged from 10 to 75 days, with a median of 30 days, and was applied once daily in 80% of the studies.

The results demonstrated statistically significant benefits of moxibustion compared with conventional medications. In 7 studies comparing moxibustion alone with pharmacologic medications, involving 461 participants, moxibustion proved superior in improving global IBS symptoms, with a risk ratio of 1.33 and a 95% CI between 1.15 and 1.55. This means that patients treated with moxibustion had 33% greater chance of presenting symptom improvement compared with those who received conventional medications. Four additional studies, involving 434 participants, evaluated the combination of moxibustion with acupuncture versus conventional medications, also demonstrating superiority of the combined therapy, with a risk ratio of 1.24.

Subgroup analyses indicated benefits for both diarrhea- and constipation-predominant IBS patients. However, when moxibustion was used as an additional therapy to conventional medications or herbal medicine, no significant additional benefits were observed. A small placebo-controlled study did not find significant differences between real and simulated moxibustion in symptom severity.

The implications of these findings for patients and health professionals are relevant but must be interpreted with caution. For patients who do not respond adequately to conventional treatments for IBS, moxibustion may represent a relatively safe additional therapeutic option. The included studies reported few adverse events, the most commonly reported being mild thirst possibly related to concurrent medication. Only 4 of the 20 studies reported safety data, limiting full assessment of the adverse effect profile.

For health professionals, these results suggest that moxibustion may have a place in IBS management, especially considering the limitations of the available conventional treatments. However, clinical implementation should consider factors such as availability of trained professionals, cultural acceptability of the therapy, and resources required for treatment.

Several important limitations must be considered in interpreting these results. First, the methodologic quality of the included studies was generally low, with many showing high risk of bias. Most studies did not adequately report randomization and allocation concealment methods, elements fundamental for preventing selection bias. More importantly, all Chinese studies compared moxibustion with other active treatments, making blinding of participants and outcome assessors impossible.

Because IBS is a condition known to show high placebo response, the absence of blinding may have overestimated the benefits of moxibustion. In addition, participants may have had cultural preferences for moxibustion over conventional medications, positively influencing results. The inclusion of only one small placebo-controlled study, which did not demonstrate benefits of moxibustion, reinforces these concerns. Other limiting factors include considerable variability in the moxibustion techniques used, treatment duration, and outcome measures, making it difficult to identify the ideal therapeutic approach.

In conclusion, this systematic review and meta-analysis provides preliminary evidence that moxibustion may offer benefits for patients with IBS, particularly when compared with conventional medications in comparative effectiveness studies. However, the limited quality of the available evidence and the high risk of bias in the included studies preclude definitive conclusions about the specific efficacy of moxibustion. Future high methodologic quality studies, including placebo-controlled trials with adequate blinding and well-designed pragmatic studies, are needed to confirm these findings and firmly establish the role of moxibustion in the current treatment of IBS. Until more robust evidence is available, patients and professionals interested