Digestive system and cystic fibrosis

The pancreas is an organ that helps your body digest food. It makes digestive enzymes, which help break down fats, proteins and carbohydrates so your body can absorb the nutrients and use them for energy. 

In people with CF, thick, sticky mucus can block the tiny tubes that carry these enzymes from the pancreas to the gut (intestine). When this happens, the enzymes become trapped inside the pancreas, instead of reaching the digestive system, where they can cause irritation and inflammation.

When the pancreas cannot release enough digestive enzymes, it is called pancreatic insufficiency. This affects most people with CF. Without enough enzymes, it is difficult to absorb nutrients from food, which can lead to poor weight gain, frequent loose or greasy stools, tummy discomfort and vitamin deficiencies. People with CF have to take supplements to replace these enzymes with their meals to help digest their food. 

Pancreatitis is when the pancreas becomes swollen and sore because the tubes are blocked. This can damage the pancreas. People with cystic fibrosis are at an increased risk of pancreatitis. It happens in about 1 in 5 people with CF who still have some pancreas function. The main symptom is tummy pain.

Chronic pancreatitis is a long-term condition where the pancreas is inflamed, scarred and painful. There’s no cure, but there are treatments to ease the symptoms.

CFTR modulator drugs are changing how CF affects the body. When started in early life, they may help protect the pancreas from damage. Some children have started making enough of their own enzymes that they need to take fewer enzymes supplements, or none at all. Research is ongoing and we are still learning about the long-term effects of these medicines.

Problems with the pancreas can also affect the cells that make insulin, the hormone that controls blood sugar levels. This can lead to CF diabetes (CFD), which affects around a third of people with cystic fibrosis.

Find out more about CFD

Because people with CF may not digest or absorb fat properly, , they may need a high-energy/calorie diet to help them grow, maintain a healthy weight and meet their body’s increased energy needs. This is very important during periods of illness or recovering from an infection, when the body uses more energy.

Poor digestion can lead to symptoms such as: 

• greasy, pale or bulky stools that are difficult to flush
• frequent and/or difficulty opening the bowels 
• constipation
• tummy pain or bloating
• nausea
• swollen abdomen
• loss of appetite
• poor weight gain or weight loss.

Medication can help. Most people with cystic fibrosis take pancreatic enzyme replacement therapy (PERT), (Creon®) with fat-containing food and drinks to help digest food.

Find out more about nutrition in cystic fibrosis

People with CF have a higher risk of developing bowel (colorectal) cancer than the general population. The risk is still low in younger people, but it increases with age, and is increased in people who have had an organ transplant. Find out more about bowel cancer, the risks in people with CF and how it is screened for.

Find out more about bowel cancer

If you're worried about cancer and would like someone to talk to, please get in touch with our friendly Helpline team.

Get support

Around 10–20% of newborns with CF present with a bowel obstruction called meconium ileus. In these cases, the meconium (a thick black material present in the bowels of all newborn babies) is so thick that it blocks the bowel instead of passing through.

Babies with meconium ileus often need an urgent operation to relieve and bypass the blockage.

Previously known as meconium ileus equivalent (MIE), DIOS is a condition that is unique to cystic fibrosis. DIOS causes blockages in the small bowel, causing symptoms such as stomach pain, bloating, nausea and weight loss. In most cases DIOS can be controlled with medication.

Gastro oesophageal reflux disease (GORD) occurs when acid and non-acid contents of the stomach move in the wrong direction and go back into the oesophagus (gullet). This can cause burning of the oesophagus or ‘heart burn’ and is thought to provoke coughing and possibly contribute to lung damage.

GORD is more common in CF because of excessive coughing, obstructive lung disease, delayed emptying of the stomach, some people eating a high-fat diet, a lax valve at the bottom of the oesophagus and other CF-specific complications.

Medicines that reduce or neutralise acid in the stomach, or surgery to strengthen the sphincter or valve at the bottom of the oesophagus, may be advised to help treat GORD. It is very common to have treatment to reduce GORD before/after a lung transplant as reflux and aspiration may increase the risk of lung rejection post-transplant.

As well as talking to your CF team about your concerns, our Helpline team offers support and a listening ear.

The charity Guts UK is also there for people with conditions affecting the digestive system.

The Trust-funded GRAMPUS-CF Strategic Research Centre aims to link the specific gut symptoms people with CF experience to what changes are taking place within their intestines. By increasing understanding of the cause of the symptoms, the researchers hope that this could lead to more tailored treatments in the future.