It sounds like the Nissen is failing. I had a Nissen in 2001. My story here: https://zarogasnook.blogspot.com/2015/08/a-long-time-passing.html .. no ads. I haven't updated in a long time. Right now I am having esophageal spasms that are creating the mucus... I cannot figure out a trigger.

My experience with gastroparesis... First diagnosed.. late 1990s or so. Every time I ate salads I had problems. I took propulsid and it helped, but they took it off the market. I tried domperine (sp) and the side effects were bad for me and it is recommended I not take reglan because of nerve problems I have. In 2008 we went on a trip out to the west coast and up to Washington State to see my brother We were in Benson Arizona and I got a stomach virus... then it hit my husband a few hours later. When it hit we were out and about and all of a sudden my vision went wacky and nausea hit. My husband sped back to campground, but I asked him to pull over because I had to throw up. I didn't really notice what I threw up.. but hubby said it was salad... looked as fresh as I had eaten two days before. It had never made it to my stomach. When we got back home I saw my GI doctor and he did an endoscopy. More greens in my esophagus from a salad I ate days before. He found a small bezoar in my stomach. I also had an ulcer. Some info on bezoars here: https://www.mayoclinic.org/diseases-conditions/gastroparesis/expert-answers/bezoars/faq-20058050 . Since high fiber and fibrous foods and most raw food can sit in the stomach a long time I was advised to not eat them. I have had less problems with gastroparesis since following this advice. I have followed it more closely since my last surgery in 2015.

If I were you I would watch my diet more closely. Look up on internet suggested diet to follow.. they should have given you a guide when you were diagnosed. Also let your doctor know what is going on. If you have to prop up with that many pillows you need more testing to see what is going on.

My vagus nerves were cut/damaged beyond repair. My life since April 2016 really has been a living hell. For example, I thought I was going to have a good day today and before I can even do anything, I am in bed with a heating pad on my gut and hoping I can make it to the bathroom when the diarrhea hits. I haven't found anything with this disorder that provides me much relief and I think I have tried everything. I see your post from last July and I wonder how you are doing? It doesn't sound like the damage from your Nissen was as bad as mine, but wondering about your quality of life and and strategies that help.