Hi....my bms are in the morning, and I drink coffee during the day. Now, on the other hand, if I were flaring and I was out, I might not drink more than one or two cups of coffee...or tea might be a better choice for me. Depends on how my gut felt. Some coffee, even the smell, can make my stomach churn.....Starbucks is one or any coffee that smells like that.....so, coffee is pretty subjective. I don't drink just ANY coffee.....
Trial and error....see how you feel. Remember, some flares, with just a bite of food or even drinking water can stimulate a bm.
Tea has astringent properties to it....and for some in my husband's family....it can constipate them...so it might be a good choice for you..lol!
Powerade has a few artificial sweeteners......I'd avoid the ones in it like the plague.....I'd never drink any artificial sweeteners....so, you might see that as part of your problem.
Drink water and take a vitamin B12 pill.