Sounds similiar to what happened to me.

About three years ago I got a swollen testicle...thought it was a
hernia...so did my doc, and she said it was not bad enough to operate
on...[JERK!}...anyway...that side was always a bit sensitive. Four
months ago I did some leg lifts[new to me] and then drove in a car for
an hour. When i got out it felt like someone kicked me in the nuts
with a metal boot!...my whole abdomen went into spasm...the area
around my pubic bone swelled and the tissue leading to my testicles
felt like cables. Lasted for two days. When I got to the doc [thought
it was that old hernia] the pain was gone/ three days later I got
severe perenuim burning and has not stopped since. Docs/Uros all say
prostatitis and prescribe cipro.....have felt NO change from
treatment. Every so often I will get a mini relapse of that first
episode of severe groin tension after a bowel movement..about once a
month. I think the two ARE related...just finding a doctor who thinks
that as well is a bitch...good luck to you