Certainly autonomic issues can cause stomach problems such as gastroparesis but don't assume it is that before having a gastroscopy/endoscopy.

I have had stomach issues for 15 months now off and on, but mostly on, since the onset on my PN last year. I wondered if it was an autonomic problem but last week after having a gastroscopy I got an alternate answer.

What they found was that I have a large para-oesophageal hernia, which essentially means that a large part of my stomach has moved into my chest through a herniation in the diaphragm. This can be quite life threatening so will probably need surgery in the very near future.

So I urge you, if you haven't already done so, to get a gastrocopy done to eliminate any anatomical and structural problems first, which may be fixable. Gastroparesis is not a nice thing to have.