Male to female Bacterial Vaginosis re-transmission

Patient: My girlfriend and I are in a monogamous relationship. She continually gets BV(bacterial vaginosis) when I ejaculate inside of her vagina with symptoms showing probably twenty to thirty minutes after intercourse. When we first started in our relationship she did not have the current birth control(IUD) that she has now.My question is why does she keep getting BV? Am I re-transmitting it? is the IUD to cause? is her body rejecting me on a microbial level? When she doesn’t have an IUD this doesn’t seem to happen but when she gets one for what ever reason BV shows up close to it.We dated 3 years ago and I had ejaculated inside of her with no side effects only til she got her first IUD that I noticed the BV odor. Going crazy with the lack of information out there and just need some medical insight

Symptoms: Occasional odor from penis apart from intercourse, minor stingy during urination and after intercourse

Doctor: Thank you for choosing ATD.Bacterial vaginosis is an infection of the vagina by a bacteria. BV is usually a mild pro blem, but it is a good idea to see a Doctor to get treated.Here are a few things which can increase BV:Many partnersVaginal douchingThe symptoms of BV are:Vaginal dischargeFishy smell from dischargeOnce the BV is diagnosed, the Doctor will start you on antibiotic therapy. This should help you achieve cure quickly.Wishing you a quick recovery.