Earlier quoted context omitted.
That reminds me of the time I learned that dates are diuretic while in Morocco. They were so delicious I would eat a bag per day. Even while swearing I must have dysentery.
I seriously doubt it. "Diuretic" means peeing, not pooping. Watermelon is a diuretic. Dates are high in fiber, potassium, sugar, and might cause a bowel obstruction.
You are correct that diuretic refers to peeing; what the poster was probably trying to say was "laxative." And foods high in fiber and sugar can certainly work as laxatives!