Professional and Linguistic Assessments Board (PLAB) Practice Exam

Meconium ileus is indicative of which condition?

1. Cystic fibrosis

2. Congenital hypothyroidism

3. Hirschsprung's disease

4. Intestinal atresia

The correct answer is: Cystic fibrosis

Meconium ileus is primarily associated with cystic fibrosis due to the thick, sticky meconium produced in these patients, which can obstruct the intestines. In cystic fibrosis, the pancreatic ducts are blocked by thick secretions, leading to impaired digestion and absorption. This results in the production of potentially abnormal meconium that is denser than normal. When this thick meconium accumulates in the intestines, particularly the ileum, it causes a blockage known as meconium ileus. This condition often presents shortly after birth and is a key clinical sign that prompts further evaluation for cystic fibrosis. In addition to meconium ileus, children with cystic fibrosis may have other gastrointestinal symptoms due to malabsorption, further solidifying the diagnosis. Other conditions listed, such as congenital hypothyroidism, Hirschsprung's disease, and intestinal atresia, may lead to intestinal obstruction but are not specifically characterized by meconium ileus in the same way cystic fibrosis is. Hirschsprung's disease involves a lack of nerve cells in the colon, leading to functional obstruction, but does not produce meconium ileus. Intestinal atresia refers to congenital blockages in the intestines that