The gene product of cystic fibrosis - the CFTR - is expressed within the gastrointestinal tract in epithelial cells of the small and large bowel, the pancreatic acini and the biliary tree, but not in the liver. For same of the manifestations of CF in the GI-tract there is a genotype-phenotype-correlation. Patients with the Delta F508 mutation present with pancreatic insufficiency (PI). PI correlates with the appearance of meconium ileus and distal intestinal obstruction syndrome (DIOS). The gold standard for the diagnosis of PI is the quantitative determination of fat in a 3-5 stool collection. The treatment consists in the administration of microcapsulated pancreatic extracts in a dose of 5.000 to 10.0000 units of lipase/kg/day. Higher doses up to 50.000 units of lipase/kg/day have been implicated with the occurence of fibrosing colonopathy in the early 90ties. As for the hepato-biliary manifestations of CF, cholelithiasis, atresia of the cystic duct and a biliary cirrhosis are the main pathologies. The focal nodular cirrhosis turns into a multilobular cirrhosis in 24% of all adults with CF combined with portal hypertension and esophageal varices. In newborn a prolonged neonatal cholestasis can occur with symptoms similar to those in extrahepatic biliary atresia. The treatment of the hepatopathy in CF is difficult. The oral administration of ursodeoxcholic acid (15-20 mg/kg/day) was shown to be effective in some studies. Up to 25% of CF patients are suffering from gastro-esophageal reflux disease (GER). An esophagoscopy is assessing the degree of esophagitis, which is treated with omeprazal. The meconium ileus of the newborn is pathognomonic for the presence of cystic fibrosis. DIOS is present in 35% of 1000 patient yea rs particularly in adolescents and adults with CF. Together with DIGS an acute appendicitis or an intusseption can be present. Since the daily dose of oral panceratic extracts has been limited, the occurence of fibrosing colonopathy has decreased. More often in the last few years a severe pancolitis was noticed in adult patients with CF due to Clostridium difficile infection. Diarrhea, abdominal pain together with signs of inflammation lead to that severe, sometime life threatening disease. The ultrasonographic visualization of the colon shows enormous enlargement of the inflamed colon easely. Rare manifestation of CF in the GI-tract comprise malignant disease like adenocarcinoma,the infection with Giardia lamblia, the development of inflammatory bowel disease, e.g. Crohn's disease and the occurence of celiac disease.
