Lately Kaji has been doing the same thing. I did the same that you did, gave him something he couldn't resist to rule out obstruction, gave him some water to make sure his throat wasn't dry. After a while I figured it out. He gulfs down his daily ration of food early in the morning. By night time his tummy is empty and he would gag and cough and throw up bile. He had always been a casual eater so I would let his daily ration out all day for him to nibble and by night he would still have some left. Now I give him his ration divided in two, one in the morning and one at night. I don't want him to go to bed with an empty tummy anymore.
Maybe your baby is doing something similar? I hope my story helps you!
__________________ Littlest JakJak 
We miss you Kaji  |