Continuos vomitting

Our child who is 20 months old is having continuous cough
resulting in vomitting. Otherwise hs is active. but underweight(19 lbs). This problem is there since he is 7 months.
It recurs almost every alternate month and becomes severe due
to which doctor put him on antibiotic (ditaclor,betnesol,vent-pd etc.).
During severe stages, he vomits every feed (almost 10-15 times)
including water. He also develops chest congestion during these times.

Please advise on what might be the disorder so that we can
take him to specialist for medication.

[National Jewish]

This is a significant problem. I would suggest seeing a Pediatric Pulmonologist as the next step to determine the cause of the cough and deal with that first. The vomiting and weight problems will all be eliminated once you have stopped the cough. There are many reasons that are possible for the cough. These need to be evaluated by a good physical examination, probably some type of x-rays etc.