After dealing with LAR syndrome for five years, I have a new doc who is much more engaged. He ordered MRI defecography and it looks like it is providing some guidance. The report indicates inability to relax the puborectalis muscle and clustering from a lack of emptying the upper portion of the neorectum. So it's off for physical therapy to see if this can help.
If you have LAR syndrome, be forceful with your doctor and get this test done. It's not as bad as I thought it would be and there is no radiation when done with the MRI. I wish I had insisted on this exam four years ago. Without definitive findings, it's easy to waste time and money chasing after things that aren't the cause of the symptoms. I'll write an update when the therapy is complete.
Here is a link for various pelvic floor dysfunctions that has good information:
https://www.fascrs.org/patients/disease ... ed-version