@jc123 Hi, Jon. Welcome to Connect.
I went through a similar thing with not being diagnosed for almost a year and a half. My symptoms were not similar to yours, just the lack of a diagnosis is. What I learned is if I ever again do not get a diagnosis here in southern NH to head right to Boston. It turned out that I had non-alcoholic cirrhosis. If I had not gotten diagnosed when I did the malignant lesions that had developed may have increased in size or number rendering me not a candidate for a liver transplant. Thankfully I was diagnosed in time and I had a liver transplant at Mass General in Boston, which is my hospital of choice. I now go there for everything except my PCP.

I realize that not everyone lives close to a Mass General or a Mayo, or Johns Hopkins, but if you do have a university teaching hospital within reach then go there. Even if it is a bit of a distance, go there. Your health is worth it. Check the US News report for top hospitals, that's a great source.
https://health.usnews.com/best-hospitals
It sounds like it could be a gastroenterology problem so you could check specifically for hospitals that are well rated for that.
https://health.usnews.com/best-hospitals/rankings/gastroenterology-and-gi-surgery
I hope you will be able to get diagnosed soon. Don't be discouraged if you have to wait for a while for an appointment. That happened to me but they put me on a waitlist and I was called much sooner than when the appointment was scheduled. I hope too that you will let us know how things are going.
If you put my Connect name, contentandwell preceded by the @ I will be alerted that I have a response.
JK