My Sister Has A Congested Cough And When She Coughs

My sister has a congested cough and when she coughs it sounds like a constricted airway! She has been to a doctor and they said her chest x-ray was clear. The doctor also said she thought it was asthma and gave her 2 inhalers and sent her to a lung specialists who in turn changed one of her inhalers to include a steroid. After a week there is no improvement and she has lost her appetite and also continues cough and vomit her food up when she tries to eat. The mucus she brings up is clear in color. Help ….any suggestions appreciated at this point!!