The goal of this study was to evaluate the antidiarrheal efficacy of $Lacteol^{TM}$-loperamide combination against the mouse model of secretory diarrhea. Secretory dirrhea was induced in mice by p.o. administration of castor oil (0.3 ml). Antidirrheal effects of $Lacteol^{TM}$-loperamide combination were compared with each individual component. $Lacteol^{TM}$-loperamide combination was the most potent among these agents, eliminating diarrhea in 100% of mice at a dose 1360/4 mg/kg (Lacteol/loperamide, respectively). In this study, we also measured changes of bodyweight as another indicator of the dirrhea, based on the assumption that lower bodyweight loss represented reduced fecal passage. The bodyweight loss of $Lacteol^{TM}$-loperamide combination administered group was 4 times lower than that of vehicle control. These findings indicate that $Lacteol^{TM}$-loperamide combination may be more potent than individual component in its antidiarrheal action, so we are going to challenge this combination for further study and clinical evaluation.