How long does the epidimys stay tender after treatment for epidimytis?

See below. It may stay tender for up to 4 weeks. Also, the pain and inflammation may recur before it is completely cured. Use anti-inflammatory meds and relative rest to overcome the pain.
It depends. Usually in cases of true infectious epididymitis, the pain and swelling will resolve for the most part during treatment with antibiotics, although residual soreness may persist for several more days or even weeks. In rare instances, chronic pain may develop. If your pain persists for more than 3 months, you should consult an urologist.