Thanks for posting your query.
As such there is no term like "Gastro bronchitis"; although there may be chances of chronic bronchitis.
Are you a smoker?
With the available described symptoms, there could be chances of acute exacerbation of chronic bronchitis.
Presence of fever
, chest tightness
and yellow phlegm suggests the diagnosis.
You should consult with internal medicine specialist/ chest physician and should go for thorough check up.
You should complete antibiotic course, mucolytics and bronchodilators.
You should also take inhalation therapy
for relief of your symptoms.
Perform gargles three times in a day; a glass of luke warm water with a pinch of salt.
Dr. Mayank Bhargava