Exocrine pancreatic insufficiency develops steadily; however, the initial reduction in secretion is practically not diagnosable. More advanced stages, which usually replicate morphological changes, can be determined with tests which asses the exocrine pancreatic capacity. Substantial damage of the pancreas and replacement of viable parenchyma with connective tissue is accompanied by the occurrence of steatorrhoea. This corresponds to a reduction in exocrine pancreatic secretion below 10% of physiological secretion. Exocrine pancreatic secretion tests are still not sufficiently sensitive for diagnosing early stages of pancreas defects and thus are not suitable for diagnostics. Furthermore, detecting reduced exocrine secretion does not provide any information about the aetiology of the disease, e.g. inflammation/tumor. The most precise test is a costly examination, including a stimulation of the gland with enterohormones; however, breath tests are usually recommended for the assessment of exocrine insufficiency therapy. Exocrine pancreatic insufficiency therapy consists of administering drugs containing pancreatin (amylase, lipase, and peptidase) to patients diagnosed with steatorrhoea, manifest pancreatic insufficiency. As standard, capsules containing microparticles of 1-2mm are recommended. They have a protective coating that prevents inactivation in the microparticles of the contained enzymes by gastric hydrochloric acid. The drug should be administered during each meal, i.e. several times a day. The most common mistake during pancreatic enzyme therapy is under dosage. The following rule applies to patients with digestive insufficiency: 40,000-50,000 UNT of lipase are to be administered during "main meals" and 25,000 UNT of lipase during morning or afternoon snacks. The drug should be taken during the meal; insufficient treatment and dosage are associated with insufficient digestion and absorption ofa number of substances and also with pancreatic malabsorption.