What Does Recurred Yellow Vomiting In A Child Suggest?

Hi, My baby is vomiting since last 3 days with frequency of 7-8 times a day. This is 2nd repeated episode in 20 days. This time his vomiting started after 1 day of running nose. he has given injection to stop vomiting and treat infection. after three day of infection he staarted with bacigyl N, Zeegut and allercet 5ml for cold. He have very indifferent and foul smell from vomiting, also today his vomiting colour turns to yellow. Please suggest why he is vomitting so much and if yellow colour vomitting of ok or should I rush again to doctor?