Abstract: 【Abstract】　Objective: To investigate the etiopathological role and mechanism of food intolerance in the diseases of irritable bowel syndrome with diarrhea ( IBS-D) in order to provide a diagnosis bases for clinical diagnosis and treatment of the diseases.Methods: The specific IgG antibodies of 14 kind of different food antigens in serum were detected by the enzyme linked immunosorbant assay (ELISA) in seventy seven cases of patients in IBS-D with Rome III and twenty six normal controls.Results: The positive rate of serum food-specific IgG antibodies was 50.6 percent in IBS-D and 15.4 percent in normal controls . there was statistically difference between the two groups (P< 0.01). there is also statistically difference between the two groups in IgG antibody levels (Z =- 3.220, P = 0.001). The positive rate of 14 kinds of serum food-specific IgG antibodies in IBS-D were and followed:egg white/yolk （32.5%）＞ tomato（14.3%）＞crab （9.1%）＞milk and soybean（6.5%）＞mushroom （3.9%）＞corn（2.6%）＞rice、 wheat、codfish and chicken（1.3%）.Only low increased levels of specific IgG to egg white/yolk、milk and tomato in normal controls were found and the specific IgG to other foods were negative. Conclusion:The abnormal humoral immune reactionsmediated by food intolerance played an important role in the immunopathogenesis of IBS-D.

Key words: 　Irritable bowel syndrome with diarrhea, Food intolerance, Immunoglobulin IgG