Cystic fibrosis is a generalized exocrinopathy in which the basic defect is still unknown. Studies have been pursued to further define abnormalities observed in these patients. Investigations demonstrating the presence of lingual lipase activity in the duodenum and the more acidic duodenal pH in the CF patients and its effect on the efficacy of exogenous pancreatic enzymes has stimulated the development of better therapeutic intervention of the digestive and nutritional problems observed in most CF patients. Thorough characterization of our CF population by both standard and investigational diagnostic criteria (ultrasonography, microbiological cultures, isoamylase) has allowed us to determine the incidence of ovarian cysts, unusual microbiological flora, and follow the progression of the pancreatic involvement in relationship to other characteristics of the disease; i.e.: pulmonary and nutritional status, and severity of infection. These correlations will aid in further clinical evaluations as well as in improving treatment.