Black coffee gives me diarrhoea but white coffee doesn’t.

[Wjdbxb]

Does anyone know the reason for this?

if I drink a black americano, I get diarrhoea. If I drink a latte or similar, I don’t. Both contain roughly the same amount of coffee, as an americano is watered down. Is the milk acting as a buffer in my digestive system or something?

Coffee is quite a harsh stimulant and aggravator if you're sensitive to it. The milk probably goes someway to changing how its digested to give a softer effect. The proteins and fats in the little bit of milk may be a protector.