CoffeeBox's digestive article attributes bathroom urgency to several compounds, but a precise sequence of molecular causes is not established by the article itself. The strongest useful observation is that some people notice bowel activity after coffee while others do not. A response is not evidence that coffee has instantly passed through the body.
Small experimental research has found a lower-colon response to both regular and decaffeinated coffee among certain responders. That makes a simple caffeine-only explanation inadequate. It also does not prove that every brew will work on a schedule or that a particular roast removes the effect.
Milk, sweeteners, serving size, breakfast and an existing digestive condition can complicate an individual's experience. Change one factor at a time if trying to understand a pattern, and avoid treating coffee as a dependable self-prescribed laxative. Persistent diarrhea, pain or a change in bowel habits deserves appropriate advice rather than a switch based solely on origin or processing. The useful coffee choice is one that fits your comfort and preferences, without assigning unsupported gut benefits to a light roast, low-acid label or fermentation style.

The conversation
A good question can make a better brew.