Pancreatic insufficiency: Sticky mucus blocks the pancreas ducts
Sticky mucus blocks the passage from a gland, called the pancreas, to the small intestine, where most of the digestion and absorption of food occurs. One of the functions of the pancreas is to make enzymes that digest food. Digestive enzymes from the pancreas enter the small intestine through a small duct or passageway. In cystic fibrosis thick, sticky mucus in the ducts in the pancreas blocks the enzymes from reaching food in the small intestine. This can lead to poor digestion and absorption of food resulting in stomach ache and problems with weight gain.
Exocrine pancreatic insufficiency occurs in the majority (85% to 90%) of patients with CF, requiring pancreatic enzyme supplements with almost every food intake.
In the milder pancreas sufficient cases, there is still sufficient pancreatic exocrine function so that enzyme supplementation is not required.
The lack of digestive enzymes leads to difficulty absorbing nutrients with their subsequent excretion in the faeces, a disorder known as malabsorption. Malabsorption leads to malnutrition and poor growth and development because of calorie loss. Individuals with CF also have difficulties absorbing the fat-soluble vitamins A, D, E and K.
Signs of maldigestion and malabsorption
Malabsorption may cause any or all of the following symptoms:
Persons with CF who have not yet started taking enzymes may have all or any of the above symptoms. Improvement is generally noted once enzymes are started. Sometimes, people with CF who already take enzymes experience these symptoms. This may suggest that the dose or type of enzymes may need to be adjusted. Do not increase or decrease the dose of enzymes without talking to your CF dietician or specialist.
Fat diarrhoea (frequent, loose and/or large bowel movements, foul-smelling stool and/or oil in the stool) is typical in CF when there’s no or insufficient enzyme therapy. But people with cystic fibrosis also experience more constipation and intestinal blockage. These blockages can lead to specific complications which are more typical for specific age groups.
Some of the children with CF are diagnosed when a newborn infant fails to pass the first stool or faeces (called meconium). This meconium may completely block the intestines and cause serious illness. This condition, called meconium ileus occurs in 5–15% of newborns with CF.
Rectal prolapse, protrusion of internal rectal membranes occurs in about 10% of children with CF and it is caused by increased faecal volume, malnutrition, and increased intra–abdominal pressure due to coughing.
Intusseption or Invagination
Intusseption is a medical condition in which a part of the intestine has invaginated into another section of intestine (to be compared to the way in which the parts of a telescope slide into one another). This can often result in an obstruction.
Older individuals with CF may develop DIOS or Distal Intestinal Obstruction Syndrome when thickened faeces causes serious intestinal blockage.
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. Over time, this can lead to scarring and cirrhosis. The liver fails to rid the blood of toxins and does not make important proteins such as those responsible for blood clotting.
There are usually no gastro-intestinal complications in pancreas-sufficient CF patients and in general, such individuals usually show a normal growth and development. But in a small group of pancreas-sufficient individuals with CF idiopathic chronic pancreatitis can occur and is associated with recurrent abdominal pain and complications.
Preventing and treating gastrointestinal problems
Learn more about how all of these symptoms and complications can be prevented, delayed or treated in the chapter Disease management (in the articles under Nutrition and enzymes and in the article Drugs and treatment for other problems in CF)