Objective: Changes in small bowel function could contribute to the complications of cirrhosis including malnutrition, infection and encephalopathy. To evaluate small bowel function, we studied intestinal permeability and luminal bacterial overgrowth in patients with cirrhosis of the liver and portal hypertension. Design: The 14C-glycocholic acid breath test was used to evaluate the presence of bacterial overgrowth and urine excretion of orally ingested 51Cr-EDTA was used to measure intestinal permeability. Intestinal clearance of α-1-antitrypsin and faecal blood loss were also measured. Setting: Gastroenterology and hepatology unit of a university hospital. Patients: A total of 18 patients were studied. Results: No evidence of small intestinal bacterial overgrowth or increased permeability of the small bowel was found. However, 28% of the patients had increased faecal blood loss. Conclusions: Although the number of patients investigated was small, our data suggest that small bowel function is maintained to a large extent in patients with advanced liver cirrhosis and portal hypertension.