Hi, Though, use of alcohol is not recommended during treatment with metronidazole and 3 days after completion of treatment due to a probability of a disulfiram like reaction in some cases. Still, effect on the vaginal discharge is not seen with simultaneous intake of metronidazole and alcohol. Definitely, in your case, this may be due to incomplete treatment, as you say yourself about missing of some doses. Other reason may be there, the presence of some mixed infection, which may require treatment with some other antibiotic etc. Last but not the least, some times recurrence of infection may be there, if you had sex with your partner, who had not been treated simultaneously and was having a dormant or an active infection. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Satnarain Bansal, General & Family Physician