Caffeine can be bad too. That does not negate the benefits it has. Everything has trade offs.
In spite of having panic attacks (linked to IBD) I still drink coffee even though both the panic attacks and the IBD would do better without it. Why? Because I also have migraines. I don't take ibuprofen for the migraines even though it is cheap, has minor side effects and it works for me because the side effects are very bad for IBD. You should see the list of side effects the drug I do take for migraines has. But those very dangerous side effects aren't a high risk for me just like nicotine's side effects aren't a high risk for me.
Ever go to a doctor and have your heart rate 80 instead of a normal 60 (my normal number)? I just did on Monday. Do you know what they said? Not a thing. 20bpm is not something that usually concerns doctors in my experience.
I've even had a 120 heart rate and they didn't bat an eye. They often ask me the usual, "do you have chest pains?" and I always answer, "Yes but I figure it's the panic attacks.", they don't care because it is something that goes along with panic attacks and I don't have other symptoms of heart problems.
With the panic, a fear of doctors and a normally low blood pressure, my BP has been all over the place including extremely high. Guess what they've said? Not a thing.
The sodium clean out stuff they gave me made me feel like I was dying, my normal BP of 117/70 was 190/100, it's not an issue, I just talked to my doctor about it. 5-10mmHg as a side effect of a drug is nothing unless you have a problem.
Nicotine is not bad for all GI issues. Just like someone shouldn't steer someone with high BP or heart problems to using nicotine you shouldn't steer someone with UC away from trying it.
I don't see anyone here doing the former, I do see you doing the later.
I was just telling someone about ecigs for her husband who has heart problems but won't quit smoking. She's an ANTZ and was throwing a fit about nicotine in them. I told her the truth, some people switch to vaping and keep nicotine because they like it, some keep nicotine for health reasons like I do, but someone like her husband would be best off without nicotine, but if it comes down to nicotine with smoke or nicotine with vapor the nicotine with vapor would probably be a better choice, only his doctor can answer that.
You need to look at the bigger picture rather than declaring something bad across the board.
I talk to my doctors when I'm there and I'm there a lot. If nicotine was a problem they would tell me, they sure didn't have a problem telling me when they thought I had Crohn's. In my picture nicotine is not bad.
I can see nictone giving you GAD, but have you ever tried 100% VG or 100% PG? My first go at ecigs was panic filled, I blamed nicotine and cut it out quickly but was no better. My second go I heard about PG sensitivity, tried my old ecigs with 0mg PG, instant panic. Got PG free juice and haven't had a problem since.