In ERCP practice, most often a combined use of guidewires is necessary to attain a therapeutic aim. E.g. a hyperflexible hydrophilic guidewire is changed after cannulating a stricture to a nitinol wire for improved stability with the use of therapeutic devices. A new guide-wire (G240) combines these characteristics with a stable shaft and a hydrophilic tip. The investigators test the hypothesis that the use of this new guidewire would decrease number of guidewires used within one ERCP session.

This is a randomized, monocentric study.

Inclusion Criteria:

• Obstruction of the biliary tract (cross sectional imaging or ultrasonography/lab data)

Exclusion Criteria:

• Operatively alternated anatomy of the patient.
• Intervention of the pancreatic duct.