The present study is a prospective, single-center study. A total of 88 patients, who had placed a pancreatic stent for preventing post-ERCP pancreatitis, will be included in the study. Aim of the study is to establish a new algorithm based on a sonographic approach to remove the placed pancreatic stents. Another aim is to compare high-end sonographic devices with devices of medium price scale one's used on the ward.

On the day of removal of the pancreatic stent, all patients receive a sonography by an experienced investigator on the ward and by another, uninformed investigator with a high-end device. If a pancreatic stent is visualized in the pancreatic duct, the patient will have an esophagogastroduodenoscopy to remove the pancreatic stent. If sonography cannot find a pancreatic stent in the pancreatic duct an x-ray will be performed as suggested by the European and international guidelines. If the pancreatic stent spontaneously dislocated into the small bowel tract according to x-ray, no further investigation will be performed. If a stent is visulized in situ by x-ray, it will be removed by endoscopyl.

Statistical analysis will be done in cooperation with the statistical biomedical institute oft he university hospital in Frankfurt.

Inclusion Criteria:

• placement of prophylactic pancreatic stent to prevent post-ERCP-pancreatitis
• age of at least 18 years
• written informed consent

Exclusion Criteria:

• diseases that prevent sonography, x-ray or esophagogastroduodenoscopy
• no given consent
• other indication for pancreatic stenting

Neither the investigator nor the patient will know before the sonographic approach, if the pancreatic stent is still in place. The diagnosis will be confirmed either by endoscopic findings or by x-ray depending on sonographic diagnosis and further algorithm.