Bollocks

Note how the bollock is actually contained within the structure of the spermatic chord = like a bag.

So a scrotum is the outer bag and within it there are 2 bollocks both contained within their own spermatic chord (bag).     It is the spermatic chords' cremasteric muscles that raise and lower the bollocks within the scrotum.

Testicular torsion --- ouch !

Scrotal Trauma - i.e. what could happen if you are kicked in the bollocks 

Severe testicular injury is uncommon and usually results from either a direct blow to the scrotum or a straddle injury. Damage occurs when the testis is forcefully compressed against the pubic bones. A spectrum of injuries may occur.

Traumatic epididymitis is a noninfectious inflammatory condition that usually occurs within a few days after a blow to the testis. Treatment is similar to that for nontraumatic epididymitis.

Scrotal trauma can also result in intratesticular hematoma, hematocele or laceration of the tunica albuginea (testicular rupture). Color Doppler ultrasonography is the imaging technique of choice.¹³ Surgical referral is required because testicular rupture requires immediate drainage and repair. Hematomas and hematoceles are managed on an individual basis.

Plenty more to read here about bollock pain

http://www.aafp.org/afp/990215ap/817.html