Baby Air

Woke up in the middle of the night and my wife was in shock, as she woke to sounds of the baby quietly choking away. She quickly tried to burp him but he was very much in distress, and I was still in the midst of waking up. Finally I snapped out of my stupor and got going, quickly laying him on the length of my arm, face down. That helped to get rid of the saliva/milk that was choking him.
It was the start of a tiring and bewildering week. From a baby with regular feeding and sleeping routine, Siyuan cried a lot, didn't sleep well or fed well. We tried everything, and he would just ignore it all, very much in distress.
Thank goodness for the maternal healthcare services provided here - giving us a 24 hours hotline to call. The nurses then assured us he was probably going through a phase where he is having a lot of stomache discomfort. Burping him more and keeping him upright would help. Warm baths will also relieve him. A friend suggested "cycling" his legs to help get rid of wind, and my mom-in-laws brought an ointment (used when we were babies and probably before that as well!) to use on his stomache.
Once we knew it was wind, at least we can stop guessing if he was hungry or sick. Then it became a matter of patiently trying to burp him and keep him upright. He fed a bit less as well, but was still putting on 250g that week, so that was okay by the nurses.
It took about a week-and-a-half for that to clear.