ObjectiveTo investigate the value of serum D-lactic acid，intestinal fatty acid binding protein （I-FABP），and E-selectin （Es） in early diagnosis of infection after gastrointestinal surgery and their relationship with curative effect and traditional Chinese medicine （TCM） syndromes. MethodsForty-nine patients with abdominal infection after gastrointestinal surgery treated in Xianju County Traditional Chinese Medicine Hospital from June 2020 to August 2023 were selected as the infection group，and another 53 non-infected patients after gastrointestinal surgery were selected as the non-infected group. The serum D-lactic acid，I-FABP，and Es levels at the first，third，fifth， and seventh days after surgery were compared between the two groups，and the Pearson correlation coefficient was used to analyze the correlation of serum indexes. The receiver operating （ROC） curve and the area under the curve （AUC） of the patients were analyzed to analyze the value of each serum index in diagnosing infection after gastrointestinal surgery. At the same time，the serum indexes of patients with different therapeutic effects were monitored dynamically on the first，third，fifth， and seventh days of treatment. Logistic regression was used to analyze the relationship between serum indexes and curative effect. The relationship between TCM syndromes and serum indexes was analyzed. ResultsThe levels of serum D-lactic acid，I-FABP，and Es in the two groups decreased on the first，third，fifth， and seventh days. There were significant differences among groups， time， and interaction （P<0.01）. On the third day，serum D-lactic acid was positively correlated with I-FABP and Es，and I-FABP was positively correlated with Es （P<0.01）. On the third day after surgery，the AUC of D-lactic acid + I-FABP + Es in the diagnosis of infection after gastrointestinal surgery was 0.861，higher than 0.727 of D-lactic acid，0.745 of I-FABP， and 0.797 of Es （P<0.05）. The levels of serum D-lactic acid，I-FABP，and Es in patients with remission infection were decreased continuously on the first，third，fifth，and seventh days. Patients with exacerbation of infection showed a continuous upward trend，and there were significant differences among groups， time， and interaction （P<0.01）. The TCM syndromes of the patients were heat toxicity syndrome，acute deficiency syndrome，blood stasis syndrome， and fu-Qi obstruction syndrome，accounting for 61.22%，20.41%，12.24%， 6.12% respectively. There were no significant differences in different syndromes，time， and interaction. ConclusionSerum D-lactic acid，I-FABP，and Es can be used for early diagnosis of abdominal infection after gastrointestinal surgery，and the change of indicators can reflect the therapeutic effect and prognosis of patients with infection，but there is no significant correlation between the change of indicators and TCM syndromes.