I can definitely tell a difference. Decaf coffee gives me either very little or no pain while normal coffee causes a fair bit of pain.
I hardly drink either though. I have maybe four cups of normal coffee a year. And maybe six cups of fancy decaf a year.
Tea I don’t drink much of either but it doesn’t seem to be causing any issues whether it’s caffeineted or not.
I used to looooove dark chilli chocolate but avoid chilli like the plague now and that includes that type of chocolate. Gave me a very bad pain. I don’t eat dark chocolate (or milk really) by itself so not sure what it’d do.
Hope this helps.