BACKGROUND/AIMS: Increased intestinal permeability has been possible contributing factors to the pathogenesis of alcoholic liver disease. Moreover, it can contribute to the development of bacterial infection and intestinal endotoxemia in patients with liver cirrhosis. This study aimed to examine the difference of intestinal barrier dysfunction between alcoholic and viral liver disease patients through the comparison of the intestinal permeabilities of patients with clinical characteristics. METHODS: Intestinal permeabilities were measured in 18 healthy controls, 41 patients with alcoholic liver disease (17 cases of alcoholic liver disease without cirrhosis and 24 cases of alcoholic liver cirrhosis) and 46 patients with viral liver disease (14 cases of chronic viral hepatitis and 32 cases of viral liver cirrhosis) by measuring 24 hour urine excretion of 51Cr-EDTA. RESULTS: The intestinal permeability was significantly increased in the patients with alcoholic liver disease without cirrhosis (5.62 +/- 2.80%), alcoholic liver cirrhosis (5.29 +/- 2.48%) and viral liver cirrhosis (3.15 +/- 1.39%) compared with that in control subjects (1.99 +/- 0.53%). On the contrary, it was not increased in the patients with chronic viral hepatitis (2.05 +/- 0.57%) versus controls. The significant correlation was not found between intestinal permeability and clinical and laboratory findings. CONCLUSIONS: The intestinal permeability was elevated in patients with alcoholic liver disease compared to those with viral liver cirrhosis. The pathophysiology of liver injury secondary to intestinal epithelial damage may be different between alcoholic and viral liver diseases.