Odour at the lower part of my body

hey guys!

i dont even know where to start from.
i have been having this problem for the pas 2 years now, and its really ruining my life.

THE PROBLEM
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there is this bad odor that emanates from the lower part of my body, i think from my genital area, its really offensive and smells like fecal matter or flatulence. i have been to a lot of doctors and still cant find a cure. some of the doctors even think am crazy. and the smell gets stronnger each time i have a constipation.

seriously i though it was hygiene at fist, but its not, cuz i maintain very good hygiene. its really bothering me and no doctor seem to have the cure. they all write me a bunch of Antibiotics all the time, but they dont work. please who out there has a clue what might be causing this :((((((((. or if someone has expirience this before, i'd like some advice

Thanks, please reply soon.