Objective To observe the clinical characteristics in the patients with post infectious irritable bowel syndrome(PI-IBS) and patients with non-PI-IBS(NPI-IBS).Methods Ninety-three patients with irritable bowel syndrome(IBS) treated in our hospital from March 2014 to June 2015 were selected,including 38 cases of PI-IBS and 55 cases of NPI-IBS.The differences of serum inflammatory cytokines levels,gastrointestinal score and gastrointestinal function were compared between the two groups.Resuits The levels of CRP,IL-18 and IL-6 in the PI-IBS group were significantly higher than those in the NPI-IBS group,and the difference was statistically significant (P＜0.05);the level of GAS,VIP and MOT in the PI-IBS group were significantly lower than those in the NPI-IBS group,the difference was statistically significant(P＜0.05);the bowel sounds score,abdominal distension and pain score and gastrointestinal reaction score in the PI-IBS group were obviously higher than those in the NPI-IBS group,the difference was statistical significance (P＜0.05);the various dimensional scores of quality of life in the PI-IBS group were lower than those in the NPI-IBS group,and the difference was statistically significant (P＜0.05).Conclusion The levels of serum inflammatory cytokines in PI-IBS patients are higher,moreover the gastrointestinal function is poorer than that in NPI-IBS patients,which can be the indicators of clinical differentiation.