The assessment of pancreatic exocrine function in children

The work on which this thesis is based began with an evaluation of different methods for non-invasive assessment of pancreatic exocrine function which might be used clinically to identify those patients in need of more complex intra-duodenal function tests. A novel modification of the Bentiromide test (incorporating para-amino salicylic acid as an internal marker for para-amino benzoic acid) was studied for the first time in children. This modified test proved to be an advance on the standard two day Bentiromide test. However, some children in this study also had chymotrypsin activity measured in faeces and this appeared potentially even more simple as a non-invasive test of pancreatic exocrine function, worthy of closer scrutiny despite the generally negative view presented in the gastroenterology literature. Subsequently, chymotrypsin activity in stool specimens proved to correlate highly with intra-duodenal secretion of enzymes following stimulation of the pancreas by intravenous pancreozymin and secretin.Ideally, a test of pancreatic exocrine function would be quantitative, accurately reflecting the degree to which enzyme secretion is impaired in different disease states. Such a test could then be used not only to identify pathology, but also to gain insight into physiological variation in enzyme secretion related to ontogeny, nutritional status, feed composition, or other influences on the pancreas.Having demonstrated that faecal chymotrypsin correlated highly with intra-duodenal secretion of enzymes following hormonal stimulation, I considered this assay might have application as a research tool in investigating: (1) the ontogeny of pancreatic exocrine function in premature infants of 32 weeks' gestation or below; (2) the relationship between faecal protease activity and risk of necrotising enterocolitis; (3) the effect of in-utero malnutrition on the exocrine pancreas.