3 week old infant boy projectile vomiting and very bad cough?

my 3 week old grandson has been having problems now for last week his eyes roll in and out of back of his head he has this horendus moan about him like he is in pain, a very bad cough and choking and gagging all the time when he eats and even after being done for some time. had him to emergency room twice two nights in a row they tell us nothing except he might have pyloric stenosis but never ask to keep him for observation anyone ever have this happen and what did they do for you? i am so unhappy with the hospitals in my area and feel like something bad is going to happen to my grandson while i am asleep.