3 months old baby has a bit cough phlegm much, cough how to do with respect to spit milk

Three months of baby a little cough sputum more than a cough spit milk, may be because cough stimulates airway mucosa and gastrointestinal mucosa caused by symptoms, can be properly fed some pear water, loquat cream, etc., can also follow the doctor's advice to use cough medicine treatment.