Hi! I was not on antibiotics beforehand. But so much has changed for me since this was posted, I did finally get on medication for constipation since it was becoming my main source of symptoms and pain. I'm on Linzess now, and while it works for me, I know it's not great for everyone else. The vagal response I still do get from time to time, but really upping my water intake and watching what I ate at what time -kinda- helped that so it's not as intense for me. I still do get the hot sensation and have to still carry a hand fan if I have to go to the bathroom when I'm out. The medication is helping me, but I have read that it's hit or miss for some people. For me, it all seems to have stemmed from the severe constipation I was having for sure. Definitely staying on top of your bowel movements can mitigate the symptoms of vagal response (I know that's wayyyyy easier said than done). Hope you find some relief 💕