Cause of thick pancreatic secretions in cystic fibrosis?

CF occurs because of mutations in the gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator). A person with CF produces abnormal CFTR protein -- or no CFTR protein at all, which causes the body to make thick, sticky mucus instead of the thin, watery kind. This blockage causes a drop in the amount of digestive enzymes the pancreas puts out. Because of this, a child with CF has trouble absorbing fats, some proteins, and fat-soluble vitamins A, D, E, and K. The problems with the pancreas can get very severe. Some of the hormone cells in the pancreas can be destroyed Ref Robbins 9/e pg 178