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Gastrointestinal Problems: Diarrhea

Gastrointestinal (GI) problems like chronic diarrhea are the second most common set of issues caused by cystic fibrosis (CF). These stools can be frequent, smelly, greasy and bloody.1,2

You can think of the GI tract as a long tube that runs from the mouth to the anus. It is responsible for turning the food you eat into nutrients that your body can use. In people with CF, virtually the entire GI tract can be affected by complications of the disease.

How does cystic fibrosis cause diarrhea?

Diarrhea is one of the signs that the pancreas is not working as it should, so your body is not absorbing nutrients properly.

That’s because in CF the mucus generated by the non-working CFTR protein clogs the ducts (tubes) leading in and out of the pancreas, which causes a condition called pancreatic insufficiency. Among its many jobs, the pancreas is responsible for releasing enzymes into the intestines that help break down food into usable parts. The mucus of CF often damages the pancreas, making it harder for the body to absorb fats, some proteins, and fat-soluble vitamins such as A, D, E and K.2

Malabsorption and diarrhea

Left untreated, this causes an issue called malabsorption, which is a failure to absorb enough nutrients. Malabsorption results in diarrhea, weight loss, smelly stools, abdominal pain, bloating, gas, acid reflux, malnutrition in all ages of people with CF, and slow growth and poor weight gain in children with CF.3

What are treatments for diarrhea?

Treatments for diarrhea in people with CF help reduce malabsorption so that nutrition improves, and painful or embarrassing side effects are reduced. Treatments usually include a combination of therapies, including:

  • Taking pancreatic enzymes and regulating the dose
  • Eating larger quantities of healthy food3,4
  • Increasing liquids, including water, electrolyte replacement drinks, juices, and coconut water2
  • Taking CF-specific vitamins that contain fat-soluble vitamins A, D, E and K, and iron and zinc.
  • Regular exercise since it is good for the digestion and the lungs.
  • If taking antibiotics, eat probiotic-rich foods such as yogurt kefir, kombucha, salt-cured sour pickles, or probiotic pills.
Written by: Jessica Johns Pool | Last reviewed: September 2019
  1. Johns Hopkins Cystic Fibrosis Center. Effects of CF: Pancreas/Gastrointestinal Tract: Pancreatic Problems. Available at: https://www.hopkinscf.org/what-is-cf/effects-of-cf/pancreas-gastrointestinal-tract/pancreatic-problems. Accessed 5/1/2019.
  2. Boston Children’s Hospital. Cystic Fibrosis | Symptoms & Causes. Available at: https://www.childrenshospital.org/conditions-and-treatments/conditions/c/cystic-fibrosis/symptoms-and-causes. Accessed 5/1/2019.
  3. Cystic Fibrosis Foundation. Pancreatic Enzymes Clinical Care Guidelines. Available at: https://www.cff.org/Care/Clinical-Care-Guidelines/Nutrition-and-GI-Clinical-Care-Guidelines/Pancreatic-Enzymes-Clinical-Care-Guidelines. Accessed 5/1/2019.
  4. U.S. National Library of Medicine. Cystic fibrosis. Available at: https://ghr.nlm.nih.gov/condition/cystic-fibrosis#. Accessed 5/1/2019.