Did your fluttering start around the time your GI issues started? Do you notice any increase in burping? Often when my pvc's act up I notice a distinct increase in gas coming up my esophagus.
Check Vitamin D and magnesium levels
That sounds like my symptoms, and mine are PVCs and PACs. Have you worn a 30 day holter monitor? That might be the best way to find out what's going on,
Sounds like Hiatal Hernia to me. Has anybody ever looked into that?
Been happening to me for most of my 58 years. Sounds like you had an echo. If so and there were no findings you're fine. These are normal kinds of events, most likely PVC's which feel like fluttering but in reality are an early beat causing a pause then a hard restart. They can be three or four beats in a row and feel like fluttering. That's what mine are.