Oh my god, I am going through the same thing as we speak. I even went to the doctor because I was so worried.
Here is what he said.
1) Do not worry; keep offering the food, the baby will take it eventually. If he is hungry during the night do not feed him, just keep offering the solids during the day. It can take about a week apparently
2) It could be teething, it certainly was with me
3) It could be a cold, at that age it apparently affects thier stomach
The waving of the arms, the turning of the head........... Oh so familiar. It was really bad for the last few day and today she was bad until teatime and she took that quite well. I am not holding my breath, see how we go tommorrow.
P.S. How are his bowels; loose or normal?