Pancreatic Insufficiency

Tests

Faecal fat. An increase in fat in the stool is often the first sign of insufficiency. The simplest test for faecal fat is to place a suspension of stool on to a glass slide, add a fat stain and observe the number and size of fat globules that are present. If the stools have the characteristic features of steatorrhoea described above, testing for fat may be unnecessary.
Trypsin test. Trypsin is an enzyme that digests protein: stool trypsin is a screening test to determine whether sufficient amounts of the pancreatic enzyme trypsinogen are reaching the intestine to be converted into trypsin.
Faecal pancreatic elastase. Elastase is a protein-cleaving enzyme produced and secreted by the pancreas. It is resistant to degradation by other enzymes and so is excreted and can be measured in the stool. The amount of this enzyme is reduced in pancreatic insufficiency. The patient’s own (human) enzyme can be measured to assess pancreatic insufficiency even if they are receiving oral (animal) pancreatic supplements that include elastase.
Immunoreactive trypsin (IRT). Raised serum values of trypsinogen show that there is obstruction of trypsinogen secretion by the pancreas into the intestine where it is normally converted to trypsin. It is used in many countries as a screening test for cystic fibrosis in newborn babies.

Non-laboratory tests

Endoscopic retrograde cholangiopancreatography (ERCP): a flexible scope is passed through the nose and stomach into the common opening of the pancreatic and bile ducts in the small intestine. It is most often used when an obstruction, for example pancreatic carcinoma, is suspected.
Secretin test (not widely used): a tube is positioned in the duodenum to collect pancreatic secretion of enzymes and bicarbonate stimulated by intravenous (IV) secretin.