OBJECTIVETo establish discriminant functions of diarrhea-predominant irritable bowel syndrome (IBS-D) by studying it from quantitative diagnosis angle, hoping to reduce interference of subjective factors in diagnosing and differentially diagnosing Chinese medical syndromes of IBS-D.

METHODSA Chinese medical clinical epidemiological survey was carried out in 439 IBS-D patients using Clinical Information Collection Table of IBS. Initial syndromes were obtained by cluster analysis. They were analyzed using step-by-step discrimination by taking information of four Chinese medical diagnostic methods and serum brain-gut peptides (BGP) as variables.

RESULTSClustering results were Gan stagnation Pi deficiency syndrome (GSPDS), Pi-Wei weakness syndrome (PWWS), Gan stagnation qi stasis syndrome (GSQSS), Pi-Shen yang deficiency syndrome (PSYDS), Pi-Wei damp-heat syndrome (PWDHS), cold-damp disturbing Pi syndrome (CDDPS). Of them, GSPDS was mostly often seen with effective percentage of 34. 2%, while CDDPS was the least often seen with effective percentage of 5.5%. A total of 5 discriminant functions for GSPDS, PWWS, GSQSS, PSYDS, and PWDHS were obtained by step-by-step dis- crimination method. The retrospective misjudgment rate was 4.1% (16/390), while the cross-validation misjudgment rate was 15.4% (60/390).

CONCLUSIONThe establishment of discriminant functions is of value in objectively diagnosing and differentially diagnosing Chinese medical syndromes of IBS-D.