Check this things 1. Is he poo ing enough 2. After feeding lay baby on your shoulder and tap on baby's back softly until gas is released . 3. Try to include more pepper , ginger etc in your daily foods.
It is common after feeding put in your shoulder and tap him.Later put in the bed
He could ve lactose intolerant also.. Please check
It is very common it mostly happens after burp
Fahmina Luqman