I also had BV.
First you need to kill the bacteria by taking the flagyl and then my doctor gave me vaginal probitic lactagyl witch has Lactobacillus acidophilus,
Lactobacillus delbrueckii subsp.Bulgaricus.
Basicly we get BV because the lactobacillus in the vagina has lost its balance. You insert them for 10 days and then to prevent BV to reoccur, just insert ones every 2 weeks and especially after your period has ended and you use tampons.