Background: Pancreatic stenting is used to factilitate major and minor pancreatic papillotomy, provides temporary drainage associated with pancreatic stone obstruction, pancreatic pseudocysts and pancreatic leaks.Pancreatic stents may occlude with time and its pathogenesis remains unclear.Aim: We performed bacteriological and SEM analyses of 9 pancreatic stents.Method: 3 blocked and 6 unblocked polyethylene stents were removed from 8 patients (1 had 2 stents).The M:F ratio is 1.6:1, and the mean age is 56 years.Indications for stenting included pancreatitis 3, pancreatitis]pseudocyst 2, pancreatic stones 3 and pancreatic leak 1.All patients received antibiotic prophyl~vSs.8/9 stents were placed for a mean of 19 days (range 2-36); one stent was in place for 2 years.After removal, the stent patency was tested by measuring the flow of sterile phosphate buffered saline through the stent.The inside of the stents was then scrapped and the sludge inoculated onto Tryptic Soy Agar plates and Brucella Sheep Blood Agar plates and cultured aerobically for 2 days and anaerobically for 7 days.Identification of isolated bacteria was performed using standard laboratory techniques.Bacterial enzymes (~-glucuronidase and phospholipase C) activities of the isolated bacteria were measured.Glutaradehyde-fixed specimens were prepared and examined with SEM.Results: 1.6 stents were patent and 3 were blocked (2 with deformity at the duodenal end probably as a result of basket removal), and 1 completely blocked by a thick, creamy-white and yellowish material.2. All stents were colonization by bacteria with 7 showing a mixed growth.A total of 20 bac-