Fig. 1

From left to right: Type 1; Regular papilla, with no distinctive features i.e. ‘classic appearance’. Type 2; Small papilla, often flat, with a diameter not bigger than 3 mm (approximately 9 Fr). Type 3; Protruding or pendulous papilla. A papilla is standing out, protruding or bulging into the duodenal lumen or sometimes hanging down, pendulous with the orifice oriented caudally. Type 4; Creased or ridged papilla, where the ductal mucosa seems to extend distally, rather out of the papillary orifice, either on a ridge or in a crease