A short course of oral ranitidine as a novel treatment for toddler's diarrhea: a parallel-group randomized controlled trial.

Background: The current paradigm for treating toddler's diarrhea comprises dietary modification and fluid restriction. Previous studies show that probiotics and proton-pump inhibitors (PPIs) or H blockers could control diarrhea associated with functional gastrointestinal disorders (FGIDs). This study aims to determine and compare the efficacy of a short course of oral ranitidine and a probiotic in the treatment of toddler's diarrhea.

Methods: This study was a parallel-group randomized controlled trial (RCT). We sequentially enrolled 40 patients who met the eligibility criteria. We randomly assigned 20 patients to the oral ranitidine group, ten patients to the probiotic group, and ten patients to the placebo group. In the oral ranitidine group, patients received oral ranitidine (3 mg/kg/day) once daily for 10 days; in the probiotic and placebo groups, they were administered 5 to 10 billion colony-forming units (CFUs) per day of lyophilized Lactobacillus rhamnosus and 50 mg of once-daily oral vitamin C tablet respectively for 10 days. Stool frequency and consistency on the 10th day of the interventions were recorded as the primary outcomes. We used the Student's t-test to determine if there were significant differences in the mean daily stool frequencies in the three intervention groups. A p-value < 0.05 was adopted as the level of statistical significance.

Results: In the ranitidine group, stool frequency decreased significantly from an average of five per day on the first day to an average of approximately one per day on the 10th day of intervention (t = 10.462, p <  0.001). Additionally, stool consistency normalized on the 10th day of intervention. In the probiotic group, there was a significant reduction in stool frequency from an average of five per day on the first day to four per day on the 10th day (t = 2.586, p = 0.041), although stool consistency remained loose. However, stool consistency and frequency were not significantly affected in the placebo group (t = 1.964, p = 0.072).

Conclusion: Oral ranitidine is more effective than probiotics in reducing stool frequency and normalizing stool consistency in toddler's diarrhea. We recommend multi-center trials with appropriate study designs to confirm and validate this finding.

Trial Registration: ISRCTN, ISRCTN10783996 . Registered 8 April 2016-Registered retrospectively.