The Gastrointestinal (GI) System

Abdominal pain is a frequent complaint in CF and the second most common reason for admission. Of all the causes only distal intestinal obstruction syndrome (DIOS) is unique to CF.

GORD, biliary disease and constipation are more common in patients with CF due to abnormal motility.

The risk of appendicitis is unchanged, however many infants would have had an appendicectomy at the same time as other lower GI surgery.

Thickened GI secretions, malabsorbtion and decreased gut motility can lead to distal intestinal obstruction or chronic constipation [10].

Pancreatic insufficiency

Ninety percent of CF patients have pancreatic insufficiency. Abnormal CFTR function in the pancreatic ducts causes loss of enzyme rich digestive secretions and bicarbonate.

Ductal obstruction and proximal inflammation contributes to destruction and fibrosis of pancreatic tissue. Consequently, absorption of lipids and fat-soluble vitamins (A, D, E, and K) is reduced, which can lead to steatorrhoea, malabsorbtion and malnutrition.

This pancreatic destruction leads to a loss of secretory cells, including insulin-producing cells in the Islets of Langerhans. The resulting CF-related diabetes (CFRD) is also aggravated by peripheral insulin resistance.

Biliary ducts

Clogging of the biliary ducts may lead to liver involvement and biliary cirrhosis, however only about 5% of CF patients develop clinical cirrhosis.

Hepatic steatosis may result from malnutrition, and congestion of the liver may result from hypoxia-induced cor pulmonale. Liver failure is the second most common cause of death in adult CF patients.

Faecal loss of bile acids is increased in CF, leading to a reduction in the bile-salt pool. About 30% of adult CF patients have a small, poorly functioning gallbladder and may develop gallstones [10].