ObjectiveTo explore the possible mechanism of Yigan Fupi Prescription （抑肝扶脾方， YFP） in treating diarrhea-type irritable bowel syndrome （IBS-D） by investigating the AKT/mTOR signaling pathway. MethodsSixty SD rats were randomly divided into control group， model group， YFP low-， medium-， and high-dose group， and pinaverium bromide group， with 10 rats in each group. All groups but the control group， were subjected to 21 days of tail-clamping stimulation and 14 days of senna leaf gavage to establish a liver stagnation and spleen deficiency-type IBS-D rat model. After successful modeling， the YFP low-， medium-， and high-dose group were administered 0.96， 1.93， and 3.87 g/（kg·d） of the prescription， respectively. The pinaverium bromide group was given 13.5 mg/（kg·d）， while the control and model groups were given 10 ml/（kg·d） distilled water. All groups were administered once daily for 14 consecutive days. General conditions of the rats were recorded during the experiment， and after modeling and drug administration， body weight， Bristol stool score， abdominal withdrawal reflex （AWR） score， and histo pathology of colon tissue were observed under HE staining. ELISA was used to detect serum levels of tumor necrosis factor α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6）. Immunofluorescence was employed to detect the levels of AKT/mTOR pathway-related proteins including phosphorylated AKT （p-AKT）/AKT and phosphorylated mTOR （p-mTOR）/mTOR in the colon tissue. Western Blotting was used to detect the levels of autophagy-related proteins， including UNC-51-like kinase 1 （ULK1）， Beclin1 and LC3， and tight junction proteins including Occludin and ZO-1 in the colon tissue. ResultsAfter modeling， compared to the control group， the body weight of rats in the other groups decreased， and Bristol stool scores， as well as AWR scores under 20， 40， 60， and 80 mmHg increased （P＜0.05 or P＜0.01）. After drug administration， compared to the control group， the model group showed reduced body weight， decreased ULK1， Beclin1， LC3Ⅱ/LC3Ⅰ， Occludin， and ZO-1 protein levels in the colon tissue （P＜0.05 or P＜0.01）， and increased Bristol stool scores， AWR scores， serum TNF-α， IL-1β， and IL-6 levels， as well as p-AKT/AKT and p-mTOR/mTOR protein relative expression levels （P＜0.05 or P＜0.01）. Pathological results showed a significant reduction in goblet cells in the upper part of the glandular layer of the colon， with mild inflammatory cell infiltration. The submucosal collagen fibers were dissolved， with unclear boundaries， pale staining， and microvascular congestion and dilation. Compared with the model group， the YFP low-， medium-， and high-dose group and the pinaverium bromide group showed increased body weight， Beclin1， Occludin， and LC3Ⅱ/LC3Ⅰ protein levels （P＜0.05 or P＜0.01）， and decreased Bristol stool scores， AWR scores under 40， 60， and 80 mmHg， serum IL-1β， IL-6， TNF-α levels， and p-AKT/AKT， p-mTOR/mTOR protein relative expression levels （P＜0.05 or P＜0.01）. The pathological morphology of the rats in the YFP groups and pinaverium bromide group showed varying degrees of improvement. Compared with the pinaverium bromide group， the YFP low- and medium-dose group showed increased AWR scores under 20， 40， and 60 mmHg （P＜0.05）. The YFP low-dose group had reduced TNF-α， IL-1β， and IL-6 levels， and increased p-mTOR/mTOR protein relative expression levels occured in all YFP groups （P＜0.05）. Compared with the YFP low-dose group， the YFP high-dose group and pinaverium bromide group showed decreased AWR scores under different pressure levels and reduced p-AKT/AKT protein relative expression levels， while the YFP medium- and high-dose group had elevated serum TNF-α， IL-1β levels and reduced p-mTOR/mTOR protein relative expression levels （P＜0.05）. ConclusionYFP can effectively improve the pathological injury of colon tissue in IBS-D model rats with liver stagnation and spleen deficiency， reduce Bristol stool and AWR scores， and its mechanism may be related to reducing level of inflammatory factors and inhibiting AKT/mTOR pathway-related proteins in colon tissue， thereby enhancing the expression of autophagy-related proteins in the colon tissue.