[The small intestines in patients with mucoviscidosis].

Cystic fibrosis (CF) is a common inherited multisystem disorder characterized by chronic obstruction and infection of airways and by maldigestion secondary to pancreatic insufficiency. The diagnosis is based on the high content of chloride in the sweat (60 mEq/l). CF is inherited as an autosomal recessive trait localized to the long arm of chromosome 7. The CF gene codes for a long 170 kDa protein, the CF transmembrane regulator (CFTR). Up to now, more than 200 mutations have been described. The basis defect is also expressed in the apical membrane of the enterocytes, especially in the secretory cells tentatively localized in the transition zone between villi and crypts. However, the intestinal manifestations of CF are more complex than just the alterations in the CFTR protein responsible for the chloride transport. Therefore, the mechanism of meconium ileus in the fetus and the newborn infant, of the duodenal acidification, of the increased permeability of a number of substances taken up by the paracellular route, of the digestive and absorptive functions of the enterocytes and of the distal intestinal obstruction syndrome is discussed.