Hi. Sorry to hear you are having these issues. They sound a lot like mine from before I started candida treatment. All except the water swishing part - not sure what that is. But, I do know that toilet bowl water can actually move on very windy days, so I wonder if maybe that is it for that one part of it?
For the other stuff, where are you at in terms of treatment? Is this your first attempt to begin figuring out what it is? What is your diet like? Are you on any meds?
It is not surprising that your internist and colon specialist couldn't help you. This is a good place to start - here on this forum. It could be candida. You are the first person I have heard with the pulsating abdomen - I had that and know just what you mean!