Testicular rupture or hematoma: This is the most likely diagnosis because a direct injury to the scrotum can cause damage to the testicles, leading to rupture or hematoma, which can result in hematuria due to the rich blood supply of the testes.

Urethral injury: An injury to the scrotum can also affect the urethra, especially if the injury is severe or involves a straddle type of trauma, leading to hematuria.
Epididymal injury: The epididymis, which is located at the back of the testicle, can be injured during a scrotal trauma, potentially causing hematuria.
Scrotal hematoma: A collection of blood in the scrotum due to injury can cause pressure on the testicles or surrounding structures, potentially leading to hematuria.

Ruptured bladder or urethra with associated pelvic fracture: Although less common, a severe injury to the scrotum could be associated with a pelvic fracture, which increases the risk of bladder or urethral rupture, conditions that are medical emergencies.
Testicular torsion: While torsion is more commonly associated with acute onset of testicular pain, a recent trauma could potentially precipitate torsion, especially if there was a pre-existing condition like a bell-clapper deformity.

Scrotal vasculature injury (e.g., varicocele rupture): Although rare, an injury to the scrotal vasculature, such as a varicocele (enlargement of the veins within the scrotum), could potentially lead to hematuria.
Tumor rupture: If there is a pre-existing testicular tumor, trauma could theoretically cause rupture of the tumor, leading to hematuria, though this would be extremely rare.