Can sexual intercourse cause gross hematuria?

Unlikely although possible (from Std or StI). Gross Hematuria is basically the presence of blood in your urine (for those who dont know). It can be extremely scary to experience, although you may not feel any pain at all. It is most commonly caused by an infection in the kidney(s) or an infection of the urinary tract.

But yes! Gross hematuria can be caused by manifestation of a possible sexually transmitted disease and or infection through unprotected sex. (to my knowledge.)