To explore the effect of Lactobacillus rhamnosus on intestinal mucosal barrier function in post-infectious irritable bowel syndrome mice. Fifty-four 8 w old Specific-pathogen free male sprague dawley mice were randomly divided into the control group (n=18), model group (n=18), and experimental group (n=18). The post-infectious irritable bowel syndrome model was established by the Trichinella spiralis infection. The experimental group was treated with Lactobacillus rhamnosus (1.0x10(7) CFU/kg, 0.5 ml), twice a day for 1 w, while the control group and model group were given the same dose of normal saline for 1 w. The changes in body weight, fecal water content, intestinal motility, and D-lactic acid levels of mice in each group were compared. The body weight of mice in the model group and the experimental group was lower than that in the control group, while that in the experimental group was higher than that in the model group (p<0.05). The fecal water content of mice in the model group and the experimental group was higher than that in the control group, while that in the experimental group was lower than that in the model group (p<0.05). The Bristoli score of the model group and the experimental group was higher than that of the control group, and the Bristoli score of the experimental group was lower than that of the model group (p<0.05). The level of D-lactic acid in the model group and the experimental group was higher than that in the control group, while that in the experimental group was lower than that in the model group (p<0.05). Lactobacillus rhamnosus can improve the intestinal motility and intestinal mucosal barrier function in post-infectious irritable bowel syndrome mice.