The first thing that comes to mind is mestinon (pyridostigmine). It’s used off label for POTS and improving motility/digestion. I take it for my POTS, gastroparesis, and intestinal dysmotility. It might be worth doing a gastric emptying study since gastroparesis can come with POTS. Or perhaps an upper endoscopy to look for gastritis, ulcers, h pylori, etc. These aren’t necessarily POTS related but can easily come with the stress of being chronically ill and can definitely make symptoms worse. If you get a diagnosis for a gi disorder, you could probably get nausea meds (like zofran or phenergan) or meds for abdominal pain. Oh also meclizine is a good drug for nausea, dizziness, and lightheadedness, so I find it’s helpful for my POTS and my gp. I’m glad you’re taking electrolytes! If you want some that you don’t need to drink (to reduce volume in your stomach), many people like salt stick. Good luck!! I hope you get some relief soon :)

I've heard about POTS being worse with food b/c of the increased blood flow to the stomach just like the blood pooling in the legs when we stand. I've experienced worse symptoms eating too, but I'm still trying to get diagnosed