Epididymitis: Inflammation of the epididymis, a structure within the scrotum attached to the backside of the testis. The epididymis is a coiled segment of the spermatic ducts that serves to store, mature and transport spermatozoa between the testis and the vas (the vas deferens).

Epididymitis is can be caused by bacteria that are sexually acquired, such as gonorrhea and chlamydia, or bacteria that come from elsewhere such as E. coli from the bowel. Sometimes no bacteria are found associated with the inflammation of the epididymis.

Epididymitis caused by bacteria is treated with antibiotics. If gonorrhea or chlamydia are suspected, both ceftriaxone and doxycycline are often used. If bowel microbes are suspected, ofloxacin may be used.