Severe vaginal infection. A fishy smell!

My frnd hd sex wd hr boyfrnd 4 months bak Nd she developed frequent urination aftr 3 days post sex.Thn at 1st she thought it ws a uti nd gt a treatment containin norflox,cital syrup nd urispas.D condition did gt better bt vaginal burning nd itching continued also white thick vaginal discharge.Thn aftr a month agn she hd sex and the conditions gt worse as d days passed.Thn 1 day lyk aftr a month of symptoms she consulted a gynaecologist bt didn't tel hr tht she's sexually active nd d doc examined her vagina externally nd she was diagnosed wid bacterial vaginitis nd fungal infection tht is d combination of 2 nd she ws prescribed brakke antibiotics(4 a week twice a day),1dose of flucanozole150 mg,lotril bg skin cream.Thn in 10 days all d symptoms disappeared nd she ws bak 2 normal Nd avoided sex.Nw a week bfore she gt d sme symptoms bt wd a less intensity nd doc agn prescribed flucon nd declared it as fungal inf.Plz help gt ol std test dne bt -ve.Bf hd a sexual past nd bf hs a fishy smell