Common causes of PEI: 1. chronic pancreatitis; 2. mild to moderate impairment of pancreatic function in the early stages of acute pancreatitis, which may have no clinical manifestations; 3. post-traumatic injury and resection of the pancreas; 4. post-gastrointestinal surgery; 5. other causes. Effect of H. pylori infection on physiological function of the pancreas The cystic fibrosis transmembrane transduction regulator (CFTR) gene and pancreatic exocrine insufficiency In 1989 Riordan et al. successfully cloned and isolated the gene associated with cystic fibrosis (CF), obtained the gene sequence and analyzed the mutation of the gene. Physiological processes of pancreatic enzymes and digestionNeurohumoral regulation of pancreatic exocrine secretionDiagnosis of pancreatic exocrine insufficiency with the above mentioned underlying disease and/or history of upper gastrointestinal surgeryClinical manifestations of digestive malabsorptionPancreatic exocrine function assay below normalAssessment of pancreatic exocrine functionDirect pancreatic function test:The secretion of pancreatic juice and pancreatic enzymes is measured in severe chronic pancreatitis by direct stimulation of the pancreas using gastrointestinal hormonesIn severe chronic pancreatitis Almost all pancreatic secretory function tests are accurate, while in the diagnosis of mild and moderate chronic pancreatitis, the average sensitivity of most indirect pancreatic function tests is less than 50% pancreatic secretion test,pancreatic secretion-cholecystokinin test,pancreaticokinin-pancreatic secretion (P-S) test,serum cholecystokinin-pancreatic secretion (CCK- The direct pancreatic function test is difficult to operate and standardize, and it is time-consuming and laborious, which can bring more pain to patients, but it is still the most reliable criterion to determine the exocrine function of the pancreas, with a sensitivity of 74-94% and a specificity of 80-98%. Indirect pancreatic function test Lundh test meal test BT-PABA test: Fluorescein laurate test (Pancreolauryl Test PLT) fecal lipid determination, normal 2 years) The use of pancreatic enzyme preparations or excessive levels of protease preparations in it, can lead to fibrosing colitis may.