Abstract
Proper identification of the Vaterian papilla is a vital prerequisite for success in endoscopic retrograde cholangiopancreatography. Overall, a "hidden papilla" situation is uncommon, often attributable to, for example, intradiverticular localizations in a setting of periampullary diverticulum. Stacked duodenal folds precluding proper endoscopic visualization of the papilla is less well discussed, with virtually no systematic data available. A concurrent presence of the former potential obstacles to an immediate recognition of the papilla has not been reported before. With a view of the sometimes challenging task of finding (and cannulating) a periampullary diverticulum-related papilla, suggestions are made to first scrutinize curtaining duodenal folds, for example, by endoscopic probing with an endoscopic retrograde cholangiopancreatography catheter as this may represent a more easily remediable cause underlying a "hidden papilla.".