ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influence of Weichang'an pill on the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D) in model rats.</p><p><b>METHOD</b>Animal model of compound diarrhea was induced by a lactose enriched diet in the Wistar rat, combining with restraint stress. Twenty four female Wistar rats were randomly divided into normal group, model group and 60 mg x kg(-1) x d(-1) Weichang'an pill group. The rate of weight increase, the incubation period of diarrhea and the diarrhea index were observed. Then 45 female Wistar rats randomly divided into five groups: control group, model group and Weichang'an pill groups of high, medium and low doses (80, 60, 40 mg x kg(-1) x d(-1)). The indexes of thymus and spleen were calculated. The activities of LDH, MDH and disaccharidase in intestinal organization were inspected. Serum D-xylose content and the AQP4 concentration in proximal colon were detected.</p><p><b>RESULT</b>After taking Weichang'an pill for 4 days, the rate of weight increase in Weichang'an pill group was higher than the model group's. While the rate of diarrhea was lower significantly. So the best cycle of taking medicine was 4 days. The indexes of thymus and spleen of model group were decreased than that of control group. And the activities of LDH, MDH and disaccharidase in intestinal organization were also decreased. But the AQP4 concentration in proximal colon was increased. Compared with the model group, the indexes of thymus and spleen increased remarkably in the group of medium doses. Meanwhile, the activities of LDH, MDH and disaccharidase increased. But the AQP4 concentration didn't change.</p><p><b>CONCLUSION</b>Weichang'an pill has the effect of antidiarrhea. It can adjust the sugar's catabolism through increasing the activity of intestinal digestive ferment.</p>