Objective To investigate the clinical effect of Lactobacillus Reuteri in adjuvant treatment of diarrhea caused by rotavirus infection in children.Methods A total of 82 children with diarrhea caused by rotavirus infection admitted to Yanzhou District Hospital of Traditional Chinese Medicine of Jining City from March 2022 to June 2023 were selected and divided into the conventional group(41 cases)and the experimental group(41 cases)according to the two-color sphere grouping method.The conventional group was treated with Montmorillonite Powder,and the experimental group was treated with Montmorillonite Powder + Lactobacillus Reuteri.The therapeutic effect,T cell subsets,duration of clinical symptoms and gastrointestinal hormone levels were compared between the two groups.Results The total effective rate of the experimental group was higher than that of the conventional group(P<0.05).The levels of CD3+,CD4+,CD4+/CD8+ in the experimental group were higher than those in the conventional group,and the level of CD8+ in the experimental group was lower than that in the conventional group(P<0.05).The duration of clinical symptoms in the experimental group was shorter than that in the conventional group(P<0.05).The levels of gastrin,motilin and vasoactive intestinal polypeptide in the experimental group were lower than those in the conventional group(P<0.05).Conclusion Lactobacillus Reuteri in adjuvant treatment of diarrhea caused by rotavirus infection in children has definite clinical effect,can improve the levels of T cell subsets and gastrointestinal hormone,accelerate the relief of clinical symptoms,and is worthy of clinical promotion.