Xyloglucan for the treatment of acute diarrhea: Methodology needs statistical rigorousness Prajakt Barde, Rhizen Pharmaceutical SA 17 December 2015 Lucio Gnessi et al.1 concluded that Xyloglucan is a fast, efficacious and safe option for the treatment of acute diarrhea. The conclusion was based on statistically significant difference in diarrheal symptoms with Xyloglucan in comparison with diosmectite and Saccharomyces in 150 adult patients. However in absence of clear prior hypothesis, it is difficult to understand whether the study sample size was adequate to conclude efficacy of Xyloglucan2. Author neither commented on the prevalence of diarrheal symptoms in control group, nor pre-defined expected difference in prevalence [effect size (d)] between Xyloglucan and control. In addition, author did not discuss the magnitude of effect of Xyloglucan and other two treatment modalities. There is understandable variability in baseline data with mean number of dehydrating stool higher in S. Bouliardii, therefore concluding on the basis of direct comparison post treatment effects would be inappropriate. Though, the result are encouraging with clear efficacy of Xyloglucan, presenting mean changes from baseline would have been appropriate to demonstrate the effect of individual drugs, to substantiate the results of the study and to build a future hypothesis. In absence of this information, it looks like a pilot study. References:1. Gnessi L, Bacarea V, Marusteri M, Piqué N. Xyloglucan for the treatment of acute diarrhea: results of a randomized, controlled, open-label, parallel group,multicentre, national clinical trial. BMC Gastroenterol. 2015 Oct 30;15(1):153.2. Charles P, Giraudeau B, Dechartres A, Baron G, Ravaud P. Reporting of sample size calculation in randomised controlled trials: review. Br Med J 2009; 338:b1732 Competing interests There is no competing interest.