Sir,

Irritable bowel syndrome (IBS) is a functional disorder of the intestinal tract, which induces abdominal discomfort concomitant with a change in bowel habit including defecation disorders. IBS is a very common disabling disorder, with prevalence of up to 24% in women and 19% in men;[1] moreover, 12% of visits to primary care physicians and 28% of visits to gastroenterologists belongs to patients meeting diagnostic criteria for IBS.[2] Despite all these unfavorable symptoms of the disease, effective therapies are lacking, and herbal agents are usually used for symptom control. Aloe vera is generally considered “safe” and few studies have investigated the efficacy of Aloe vera in the treatment of IBS. We entered 33 patients consecutively attending our clinic with constipation-predominated refractory IBS into an 8 week treatment course with Aloe vera including a weekly follow-up for evaluating treatment efficacy; and in each session, a new Aloe vera bottle would be given to patients. Aloe vera juice was administered 30 ml twice daily. Visual analog scale (100 mm) questionnaires were used on a daily schedule to assess the variables. The mean ± SD of pain/discomfort at the baseline level was 4.2 ± 0.8, which decreased to 0.3 ± 0.6 at the end of the study (P < 0.001). The mean ± SD of flatulence decreased from 3.7 ± 1.2 at baseline to 0.3 ± 0.6 at the end of the study (P < 0.001). Stool consistence, urgency, and frequency of defecation (P > 0.5 in all) reacted not to Aloe vera therapy. Potential criticism may arise over our study's methodology. The first and most important thing is that our trial was not placebo-controlled. Since placebo has been proven to have symptom-relieving effects on IBS, interpretation of our study findings, without comparing them to placebo treated patients can raise controversial debates. “Refractory” IBS was defined when patients were not satisfied with their current treatment. On the other hand, our study has several powerful points. First of all, we separately surveyed symptoms of the patients one by one based on self-rated scales; however, in most previous studies, patients were evaluated by quality of life questionnaires, which are nor specific to IBS, and does not show the distinct impact of Aloe vera on patients complaints. To our knowledge, it is the first study using self-rated questionnaires that shows Aloe vera can reduce pain/discomfort of patients with IBS. In a previous study, Odes and Madar[3] failed to find any association between Aloe vera use and pain reduction in patients complaining constipation. Moreover, Hutchings et al.[4] and Davis et al.[5] also found no beneficial effect for Aloe vera on the IBS symptoms. In conclusion, Aloe vera can reduce abdominal pain/discomfort as well as flatulence in patients with constipation predominated IBS while it is unable to improve urgency and frequency as well as consistency of stool in these patients. Further, placebo-controlled studies with larger patient population are needed to confirm our results.