: 1253  In these milder cases, sufficient pancreatic exocrine function is still present so that enzyme supplementation is not required. : 1253  Usually, no other GI complications occur in pancreas-sufficient phenotypes, and in general, such individuals usually have excellent growth and development. : 1254  Despite this, idiopathic chronic pancreatitis can occur in a subset of pancreas-sufficient individuals with CF, and is associated with recurrent abdominal pain and life-threatening complications.Thickened secretions also may cause liver problems in patients with CF. Bile secreted by the liver to aid in digestion may block the bile ducts, leading to liver damage. Impaired digestion or absorption of lipids can result in steatorrhea. Over time, this can lead to scarring and nodularity (cirrhosis). The liver fails to rid the blood of toxins and does not make important proteins, such as those responsible for blood clotting. Liver disease is the third-most common cause of death associated with CF.Around 5–7% of people experience liver damage severe enough to cause symptoms: typically gallstones causing biliary colic. Endocrine
The pancreas contains the islets of Langerhans, which are responsible for making insulin, a hormone that helps regulate blood glucose. Damage to the pancreas can lead to loss of the islet cells, leading to a type of diabetes unique to those with the disease. This cystic fibrosis-related diabetes shares characteristics of type 1 and type 2 diabetes, and is one of the principal nonpulmonary complications of CF.Vitamin D is involved in calcium and phosphate regulation.
Once within the lungs, these bacteria adapt to the environment and develop resistance to commonly used antibiotics. Pseudomonas can develop special characteristics that allow the formation of large colonies, known as "mucoid" Pseudomonas, which are rarely seen in people who do not have CF. Scientific evidence suggests the interleukin 17 pathway plays a key role in resistance and modulation of the inflammatory response during P. aeruginosa infection in CF. In particular, interleukin 17-mediated immunity plays a double-edged activity during chronic airways infection; on one side, it contributes to the control of P. aeruginosa burden, while on the other, it propagates exacerbated pulmonary neutrophilia and tissue remodeling.Infection can spread by passing between different individuals with CF. In the past, people with CF often participated in summer "CF camps" and other recreational gatherings. Hospitals grouped patients with CF into common areas and routine equipment (such as nebulizers) was not sterilized between individual patients. This led to transmission of more dangerous strains of bacteria among groups of patients.