There has been tremendous growth in the population of adults with cystic fibrosis (CF). This demographic change has created the need for special clinics to care for adults with CF and has resulted in an awakening of interest in CF among physicians caring for adults. The protean and varied manifestations of CF disease in multiple organs call for expanded knowledge of the condition among physicians in a wide variety of subspecialties, including, but not limited to, pulmonary medicine, gastroenterology, hepatology, clinical nutrition, endocrinology, infectious diseases, rheumatology and andrology. This review will focus on disease pathobiology of the gastrointestinal and hepatic manifestations of CF disease which the internist is likely to encounter.

We will first examine the clinical manifestations of CF disease that are directly associated with loss of function of the cystic fibrosis transmembrane regulator (CFTR) protein and then summarise those which are secondary. We will elaborate the challenges of establishing or excluding a CF diagnosis in patients who present de novo in adulthood, with particular attention to conditions with CF-like phenotypes that are associated with an increased frequency of mutations in the CFTR gene. Finally, we will briefly discuss emerging knowledge of the potential contribution of mutations in the CFTR gene to other complex genetic conditions.

Over the past three decades the most striking result of advances in the care of patients with CF has been the dramatic improvement in survival. Whereas median survival in the United States was only 16 years in 1970, it has risen to over 32 years in 2005. For patients born in the 1990s median survival is predicted to exceed 40 years.¹ Of patients born in the United Kingdom in 1980, 82% were alive at age 20, whereas for children born in 1990, 96.5% are alive at age 15 (fig 1).² As …