Hidden sources of Caffeine

Stimulates gut motility and can trigger urgency, cramping and reflux in sensitive people.

Where it hides

Decaf coffee/tea — "decaffeinated" still means trace amounts (roughly 2-15mg per cup), which can add up over several cups
"Natural flavors" in flavored sparkling waters or sodas — can include guarana, kola nut, or yerba mate extract without the word caffeine on the front label
Pre-workout powders, weight-loss supplements, and some multivitamins — often use guarana or green tea extract as a stimulant, listed only in the small-print ingredient panel
Headache and cold/flu medications (e.g. Excedrin, some Midol/Anacin formulas) — caffeine is added to boost the pain reliever's effect and is easy to miss when you're just grabbing something for a headache
Coffee- or mocha-flavored desserts and dairy (tiramisu, coffee ice cream, mocha yogurt) — flavoring is often made from real coffee or espresso powder, not just "coffee flavor"
Kombucha — brewed from tea, so it carries residual caffeine even though it reads as a probiotic drink, not a tea

Information only — not medical advice or a diagnosis. Settle structures a self-experiment and helps you track what you observe.