Definition

Chronic pancreatitis describes a wide range of irreversible progressive diseases of the pancreas in which recurrent inflammatory processes result in substitution of normal pancreatic parenchyma by fibrous connective tissue（Hoffmeister et al.2015）.Thus，the exocrine and endocrine functions of the pancreas are gradually lost.Patients with CP often have intricate symptoms，such as abdominal pain，steatorrhea，malnutrition，diabetes type 3c and gut dysmotility.Pain presents to be the main typical symptom of patients with CP.Besides，further characteristic complications may arise，such as pseudocysts，stenosis of pancreatic duct or bile ducts，duodenal obstruction，vascular complications，malnutrition and chronic pain.CP is one of the vital risk factors of pancreatic carcinoma.It significantly reduces the quality of life and the lifespan of relevant patients（Mayerle et al.2013；Ito et al.2016）.(https://www.daowen.com)

The definitions above only centers morphology.Advances in epidemiology，molecular genetics，biochemistry，modeling and other disciplines have new understandings of pathogenesis of CP，and allow the specialists reach an initial agreement on a mechanistic definition—“Chronic pancreatitis is a pathologic fibro-inflammatory syndrome of the pancreas in individuals with genetic，environmental and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress”.In addition，‘Common features of established and advanced CP include pancreatic atrophy，fibrosis，pain syndromes，duct distortion and strictures，calcifications，pancreatic exocrine dysfunction，pancreatic endocrine dysfunction and dysplasia’（Whitcomb et al.2016）.The definition recognizes the complex character of CP and departs risk factors from disease activity markers and disease endpoints.If international consensus is reached after debates in rebuttals and indorsations among experts and pancreatic societies，the definition would be of great benefit to early diagnosis，classification and prognosis.