BACKGROUND: The high choledocholithiasis recurrence rate after choledocholithotomy plus T-tube drainage is related to biliary bacterial infection. These bacteria are from the intestine, either via the major duodenal papilla, or the penetrating intestinal mucosa. It is therefore possible that duodenobiliary reflux and increased intestinal permeability exist in patients who have undergone choledocholithotomy. This study was undertaken to find the evidence of duodenobiliary reflux and to assess intestinal permeability in these patients. METHODS: Twenty-one patients who underwent choledocholithotomy plus T-tube drainage 2 months ago, and 11 healthy volunteers (controls) took orally 185MBq of 99mTc-DTPA. The patients’ bile was collected in the next 2 hours via a T-tube and the 99mTc-DTPA radioactivity in the bile was counted. Intestinal permeability was evaluated by measuring the 24-hour urinary excretion rate of ingested 99m Tc-DTPA in both patients and controls. RESULTS: In 6 of the 21 patients, radioactivity in the bile was detected. The intestinal permeability was significantly higher in patients (11.45% ±6.16% ) than that in controls (3.61%±1.63%, t=3.28, P<0.05). CONCLUSIONS: Duodenobiliary reflux exists in patients who have undergone choledocholithotomy plus T-tube drainage. The intestinal permeability is higher in these patients than in healthy subjects. Duodenobiliary reflux and increased intestinal permeability may be factors of cholelithiasis recurrence. BACKGROUND: The high choledocholithiasis recurrence rate after choledocholithotomy plus T-tube drainage is related to biliary bacterial infection. These bacteria are from the intestine, either via the major duodenal papilla, or the penetrating intestinal mucosa. It is therefore possible that that duodenobiliary reflux and increased This study was undertaken to find the evidence of duodenobiliary reflux and to assess intestinal permeability in these patients. METHODS: Twenty-one patients who underwent choledocholithotomy plus T-tube drainage 2 months ago, and 11 Healthy volunteers (controls) took orally 185MBq of 99mTc-DTPA. The patients’ bile was collected in the next 2 hours via a T-tube and the 99mTc-DTPA radioactivity in the bile was counted. Intestinal permeability was evaluated by measuring the 24- hour urinary excretion rate of ingested 99m Tc-DTPA in both patients and controls. RESULTS: In 6 of the 21 pa The intestinal permeability was significantly higher in patients (3.41% ± 1.63%, t = 3.28, P <0.05). CONCLUSIONS: Duodenobiliary reflux exists in Patients who have undergone choledocholithotomy plus T-tube drainage. The intestinal permeability is higher in these patients than in healthy subjects. Duodenobiliary reflux and increased intestinal permeability may be factors of cholelithiasis recurrence.