Hallow Dear, Brown discharge denotes either the stale blood or decaying tissue getting excreted. If such discharge has been noted only for last few days, and the intercourse took place immediately after menstruation, it is likely that some amount of the blood stagnated inside the uterine cavity is gradually coming out. It does not need any treatment. Any cervical lesion like erosion also can give rise to such discharge. In that case, usually there is low back ache also. It can be cured by cauterization of the cervical erosion under antibiotics umbrella. You have not mentioned your age. If you are in advanced age group, you will have to get cancer of the cervix ruled out. Pap smear examination following vaginal examination will help to do this. Please report to your Gynaecologist and get examined vaginally and undergo any subsequent investigations if required. I hope this helps you. Dr. Nishikant Shrotri