I have precisely the same symptoms and my doctor(s) have been unable to diagnose the condition. It's been gonig on for about two years now. If you make any progress in diagnosis of the condition please post comments here.
Thanks.
This is a most unusual symptom but your suggestion of a hernia, hiatal or other, is a good one. The sensation could well be enhanced by the presence of food in the herniating portion of bowel. A plain chest x-ray might provide an answer and that should be the first step. If that fails to provide an answer, a barium swallow would be the next step. If that fails to provide a diagnosis, you should ask your doctor about an abdominal CT scan. Granted, this is most likely a benign condition, but it something you have never experienced before and there is always the slight chance that this could be the first sign of something more serious.
You might also ask your primary care physician (PCP) to ask one of his GI specialists if he/she has ever encountered a person with this symptom.