What accounts for growth failure in a child with cystic fibrosis?

Growth failure in a child with cystic fibrosis primarily occurs due to impaired digestion and absorption resulting from a deficiency of pancreatic enzymes. Cystic fibrosis affects the pancreas, which becomes obstructed by thick, sticky secretions. This obstruction hinders the release of digestive enzymes, leading to malabsorption of nutrients, especially fats and proteins, critical for growth and development. As a result, children with cystic fibrosis can experience significant nutrition deficiencies, contributing to growth failure.

While the other options may relate to challenges faced by children with cystic fibrosis, they do not directly account for the primary cause of growth failure. Dyspnea and shortness of breath might lead to decreased appetite, but it is the malabsorption due to pancreatic enzyme deficiency that most significantly impacts growth. Increased bowel motility can affect nutrient absorption, but in cystic fibrosis, the main issue is the lack of pancreatic enzymes. Lastly, pulmonary obstruction can cause oxygen deficit and impact overall health, yet it is the nutritional aspects stemming from impaired digestion that predominantly leads to growth failure in these children.