Objective To study the changes in intestinal permeability in patients with gallstones of different distribution and properties and to in-vestigate the role of intestinal barrier function in gallstone formation.Methods A total of 108 patients with gallstones in our hospital in need of op-eration from March 2011 to March 2013 were enrolled in this study.Twenty healthy controls were also included.According to the distribution of gallstones,the subjects were separated into the following four groups:normal control group (group A1),gallbladder stone group (group B1),bile duct stone group (group C1),and combined group (group D1),in which gallbladder stones were complicated by bile duct stones.All patients un-derwent operation,and gallstones were collected for chemical analysis.According to the chemical properties of gallstones,the subjects were re-grouped as follows:normal control group (group A2),cholesterol stone group (group B2),pigment stone group (group C2),and mixed stone group (group D2),in which cholesterol stones were mixed with pigment stones.D-lactic acid level and diamine oxidase (DAO)activity in plas-ma and mucosal tissue of the terminal ileum were measured by spectrophotometry.Differences were analysed by ANOVA and LSD t-test.Results Plasma D-lactic acid level and intestinal DAO activity showed no significant differences between groups A1,B1,C1,and D1 (P>0.05). Chemical analysis after surgery found 40 cases of cholesterol stones (37.04%),52 cases of pigment stones (48.15%),and 16 cases of mixed stones (14.8%).Group C2 showed significantly different D-lactic acid level and DAO activity compared with B2 and A2 (P<0.05 ),but no differences from D2 (P>0.05).Group B2 was found of no differences from A2 and D2 (P>0.05).Conclusion Patients with pigment stones were all found of changes in intestinal permeability.The formation of pigment stones is related to impairment of intestinal barrier function.It is possible that impairment of intestinal barrier function plays a certain role in pigment stone formation.