I too have terrible swallowing issues. Mornings are worse for me. And it comes in flares during the day. I’ve been told it’s due to vagus nerve damage. After many doctors nobody has been able to give me any help either. I do take a small amount of klonopin when the flares are severe and it seems to help some. It works on the cns which in turn seems to help with the swallowing. It is labeled an addictive drug so you need close monitoring Talking too much or any stress makes swallowing much worse for me so I have social anxiety along with it. I’m so sorry your son is dealing with this problem. It is hard to explain to people how terrible this symptom can be. I am considering the Parasym plus with hopes of it helping this problem but need to get my digestive issues calmed down before starting since from what I’ve read helps people with bowel paralysis. I have the opposite problem unfortunately. Have you tried this supplement with your son yet?
Best regards
T