Pancreatic exocrine insufficiency (PEI) is the inability of the pancreas to produce and/or transport enough digestive enzymes to break down food in the intestine and allow its absorption. It may be due to problems arising in the pancreas itself or problems outside the pancreas. The most common cause is chronic pancreatitis as a result of long term pancreatic damage caused by a variety of conditions. Other causes of pancreatic insufficiency include cystic fibrosis, obstruction of the pancreatic duct system due to a tumour or a stricture, gastrointestinal tract and pancreatic surgical procedures, and rarely Shwachman-Diamond Syndrome (SDS), untreated coeliac disease or Crohn’s disease, and autoimmune pancreatitis. In children it is most frequently associated with cystic fibrosis and in adults it may follow chronic pancreatitis or repeated attacks of acute pancreatitis.
Pancreatic exocrine insufficiency usually results in symptoms of malabsorption, malnutrition, vitamin deficiencies, and weight loss (or reduced weight gain in children). The most common complaint is diarrhoea, which is frequently watery. It is due to fat malabsorption and is characterised by pale, fatty, foul-smelling, floating stools (steatorrhoea). Flatulence (wind), abdominal distension and cramps are also some of other symptoms. Adults with pancreatic insufficiency may also develop diabetes.