Many years ago I had a boss who had terrible BO, it was not "fecal" nor simply stale sweat, it was really hard to describe but it permeated his entire office so even when he was not in it it smelled of him. A few years later after I didn't work there anymore I encountered one of my ex-coworkers and while conversing she told me he'd finally gotten cured, the reason for his BO was a lack of vitamin B-12. I'd never heard of that before and to date haven't heard of another case like that either.
I also heard in the TV show "Know The Cause" that a systemic fungal infection can cause BO. Even vegeetarians are consuming a lot of fungus laden foods all the time, that coupled with maybe some exposure to mold or the use of antibiotics when your were growing up (or how about 8 years ago???) could be responsible for that. Naturally, the liver has something to do with keeping us odor free too as it filters and deactivates all kinds of noxious substances but a fungal problem can definitely slow it down so you may want to give your liver some support.