I am a 41 year old female 5 4 and obese. I have never had any children and I have not been sexually active for about 10 months now. I have had trich in the past as well as bacterial vaginosis . I do also have endometrosis. My question is I have brown staining on my panties in the crotch area. I know this is not a fecal stain for sure. I don t notice a smell and this is a contstant thing it doesnt just happen at certain times it is ongoing. What can this be?