How cystic fibrosis can manifest in the gastrointestinal system

In the February 2020 issue of Contemporary Pediatrics, Drs. Anna Reed and Darla Shores provide a briefing on the care of cystic fibrosis (CF) with a focus on the gastrointestinal complications. Although CF primarily affects the lungs, it is a complex disorder that involves multiple organ systems and many aspects of patients’ lives.

What the primary care provider should know

Although the majority of patients with CF will be managed by specialty care, the primary care provider (PCP) is often the first line of contact for many routine concerns. When encountering a patient with CF in the primary setting, Drs. Reed and Shores indicate that there are extrapulmonary symptoms that must be considered in patients. For instance, in the infant with CF, weight and length should be monitored more often than with other children. Any deviations from the expected growth pattern should be promptly addressed. Given the increased caloric needs for infants with CF, breastfeeding mothers may need to supplement with formula or families receiving assistance to purchase formula may require documentation of the medical need for the increased consumption.

It is also important for the PCP to keep CF in the differential diagnosis for patients with poor weight gain who had a normal newborn screening result for trypsinogen. As the authors mention, pancreatic insufficiency is often present at birth, but may not develop until later in life. Steatorrhea and weight loss should prompt an evaluation for of fecal elastase, and if abnormal, should result in referral to a specialist for further workup. Sweat chloride testing is also an option for testing for CF, but in the setting of gastrointestinal symptoms, fecal elastase is an appropriate first step.

Expanding the differential diagnosis in gastrointestinal complaints

In a patient known to have CF, gastrointestinal complaints should be evaluated promptly and thoroughly. The primary pathophysiology of CF can affect gut motility and the gut microbiome, setting patients up for a higher risk of a variety of conditions throughout life, including meconium ileus in the neonatal period and intussusception in later childhood. Emergency care clinicians and hospitalists should also be aware that patients with CF may present with atypical findings for common disorders such as appendicitis, and the authors provide a table to reference when assess right lower quadrant pain.

The frequency of abdominal pain in patients with CF is high, up to 50-60% according to the authors. The fact that the complaint is common or even chronic in a patient, does not preclude the need to provide a thorough work up of the pain at onset or with a change in the character or location of the pain. The differential diagnosis of abdominal pain in patients with CF is extremely broad, and patients may be misdiagnosed or underdiagnosed for conditions, include celiac disease and Crohn disease.

The future of caring for CF

As the underlying pathophysiologies of CF continue to be investigated and further understood, therapies and treatments for the disorder will continue to improve the life expectancy and quality of life for patients with CF. Therefore, all primary and specialty providers will need a basic knowledge of the unique needs for these patients in order to help them achieve their maximum potential.

Susan Kirk, Member-at-Large and Board Member of SPAP, received her Bachelor of Science in Biological Engineering at Mississippi State University and Master of Physician Assistant Studies at the University of Kentucky. She has practiced in pediatric hematology/oncology for her entire PA career, currently at Texas Children's Hematology Center and Baylor College of Medicine. She enjoys sharing her passion for hematology with the next generation of medical providers.