I've been falling back into old habits, drinking 1 in the morning and another later in the day. Treating myself on the weekend to extra shot lattes from various coffee establishments. It didn't help that I was ill for 2 weeks and massively tired. My guts haven't thanked me for it that's for sure. Starting today I'm going to have to cut it down, hoping to find a balance where I can co-exist with caffeine without mild IBS.
I only managed a week without caffeine and now I'm back on it. Didn't feel much different really, I probably didn't give it long enough, mind you.
I'm now having two/three coffees prior to 12pm and one decaff or sometimes nothing afterwards, which seems to keep my sleep in check. Also, I wait an hour after waking before my first cup. I'd watched a video on cortisol levels in the morning and found that my double shot espresso in the morning - twenty minutes after waking up - probably wasn't the best idea...
I have IBD (Ulcerative Colitis), I know some people have trouble with their stomachs and caffeien but it seemingly has zero effect on me.