question: hi, i am a 21year old male and have been suffering with cystitis since 8yrs old, i drink lots of water and cranberry juice and do not suffer from it when urinating.since being sexually active i have started getting the same pain a cystitis but after ejaculation. i do not get the pain during sex or whilst i am ejaculating, only after. i am then on the loo for up to an hour drinking water to flush it through. i have been to the doctors several times with the same problem but am getting nowhere.