Abstract：【Objective】To study the clinical features and expressions of IL-17A，IFN-γ，and IL-10 in serum and intestinal mucosa of patients with post-infectious irritable bowel syndrome and non post-infectious irritable bowel syndrome.【Methods】44 diar? rhea-predominate IBS patients（21 with PI-IBS，23 with NPI-IBS）and 10 healthy controls were recruited in this study. Investigation questionnaires of GSRS，SAS，SDS were carried out to evaluate the gastrointestinal function，anxiety status and depression status of IBS patients. The expressions of IL-17A，IFN-γ，and IL-10 in intestinal mucosa and serum were measured by immunohistochemis? try（IHC）and enzyme-linked immunosorbent assay（ELISA）.【Results】The SDS scores of NPI-IBS patients were higher than those of controls（P < 0.05），and the SAS and SDS scores of PI-IBS patients were higher than those of controls（P < 0.05）. The GSRS， SAS and SDS scores of PI-IBS group were higher than those of NPI-IBS group（P < 0.05）. Compared with healthy controls，PI-IBS and NPI-IBS group showed significant rise of IL-17A，IFN-γ levels and decrease of IL-10 level in intestinal mucosa（P < 0.05）；In serum，the IL-17A levels were up-regulated and the IL-10 levels were decreased in PI-IBS group but not in NPI-IBS group whenthan those in NPI-IBS group（P > 0.05）.【Conclusion】PI-IBS and NPI-IBS patients existed various anxiety and depression. The levels of IL-17A and IFN-γ increased and level of IL-10 decreased in PI-IBS and NPI-IBS group. But the clinical symptoms and changes of cytokines of PI-IBS patients were more significant. There may exist other pathogenesis in PI-IBS but not in NPI-IBS.