Final answer:
Bronchoscopy is not essential for diagnosing cystic fibrosis; the diagnosis is typically made using a sweat chloride test.
Step-by-step explanation:
The statement that a Bronchoscopy test is essential in establishing the diagnosis of cystic fibrosis (CF) for a toddler is false. Commonly, the diagnosis of CF is made based on symptom presentation, family history, and a sweat chloride test, which measures the amount of salt in sweat and is considered a gold standard test for CF. This is because CF is caused by a mutation in the CFTR gene, which leads to the production of sticky mucus that clogs respiratory and digestive organs. Although bronchoscopy can be useful for assessing lung infection status and evaluating the anatomy of the airways in a patient already known to have CF, it is not typically used to diagnose the underlying CF condition itself.