I get these symptoms. Mine is due to a hiatal hernia and poor digestion. It is getting to the point where I do not want to even eat or drink water. If I slouch or lay down after eating, I will really notice them. Also, when I hear my tummy gurgle and it gets near to having a BM, I will notice them. I hate them. I have had an ECHO, holter monitor and blood work, they are come back fine. I have also tried digestive aides, now, I know lots of folks swear by them, by they do not help me at all. Sometimes I just want to curl up and cry, but, if I curl up, I will get a PVC's. Ugh.
I think the reason you have not gotten any answers is because there is a regular hearty rhythm forum here, and that is where most post about the PVC's and such. This one is more for heart disease.