The importance of chromoduodenoscopy in the diagnosis of diseases of the extrahepatic biliary tract

Fibroendoscopic methods of studying the esophagus, stomach, duodenum and diseases of the pancreatobiliary zone have long earned recognition due to their high efficiency. However, mild inflammatory changes in the mucosa of these organs, as well as tumor lesions in the initial stage, especially located in relatively inaccessible areas for examination, are often incorrectly regarded during fibroendoscopy even by an experienced endoscopist [1]. Therefore, it is understandable that researchers strive to increase the effectiveness of fibroentoscopy by using either magnifying optics or contrasting areas of mucosal lesion [1, 4, 5].