Thank you for your query on Healthcare Magic.
Frequent upper respiratory tract
and gastrointestinal infections are common in children below the age of 6 years and it is due to frequent exposure to common pathogens.
After 6 years they are immune to most of the common infections and the frequency of disease will decreases.
Nothing to worry.
Give him balanced and nutritious diet.
Avoid exposure to cold
air, smoke, pollution, pets, and dust.
In infancy, the spitting was due to gastroesophageal reflux and it is not related to his present complaints.
Hope I have answered your query. if you have any clarification please let me know.