CCK and cystic fibrosis: EPI in children and adolescents can be caused by (1) insufficient pancreatic stimulation (e.g., in CD by reduced release of cholecystokinin from the duodenum), (2) reduced synthesis of pancreatic juices (e.g., by damaged pancreatic tissue in cystic fibrosis or chronic pancreatitis), (3) obstruction of the pancreatic duct (e.g., in cystic fibrosis or in anatomical defects of the pancreatic ducts) [91, 92] (Table 2).