Cystic fibrosis is a hereditary disease well known to paediatricians. Over recent years, its prevalence among the adult population has dramatically increased; thus becoming a disease increasingly seen in adult practice. Cystic fibrosis is a multi-organ disease, with a wide spectrum of clinical manifestations involving many organs. The aim of this article is to review the digestive system manifestations of this disease: the involvement of the gastrointestinal tract, liver, biliary system and pancreas, with a special emphasis on the adult population.