Hi, Well, the cause of the yellowish or brown vaginal discharge is a common and usually harmless issue. Occasional spotting between periods might have this appearance and can be normal, especially if you re taking low-dose birth control pills. So in most cases, this does not indicate a sign of disease. If it is, then usually this indicates bacterial vaginosis, STD or polycstic ovarian syndrome. Less common, some other hormonal disorders may be present. In some cases, however, a yellow or brown vaginal discharge could indicate a serious problem. Although brown and yellow vaginal discharge often does not indicate a serious problem, it should not be ignored if it persists, recurs or is accompanied by other symptoms and then you should see gynecolgosit for further work up. In some cases, a yellow or brown vaginal discharge could indicate a serious problem. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Ivan R. Rommstein, General Surgeon