I don't have all the answers but staying away from sugar, meats and food high in choline has been helping me. Also taking primadolplus and activated charcoal, and vitamin K has been helpful to me and has been helpful in ridding my body of fecal smells, also chrolloplyll. I'm not saying that vitamin K will take away all odors but you won't be smelling like fecal odors, I take it twice daily after a meal. And diet plays a very big role and cleansing of the colon too because the odor is coming from the gut because that's where the choline is stored inside the gut (if it's TMAU related). There are certain vitamins that are helpful for the body such as vitamin B2,B12,and B6 and vitamin C is suppose to be good for the body and try magnesium and zinc they are supposedly good for foot odors and ridding the body of secretions that contribute to body odors, and taking folic acid is helpful for the body too (If it's TMAU related)but I know that if it's TMAU it would affect your urine smell and since taking activated charcoal 1000 a day the TMAU smell is gone from my urine, but like I said these things have been very helpful to me but staying away from dairy is important too because that definitely does contribute to the fecal smell.I'm not a doc but I hope this info has been helpful,but go on line and do your research too. I remember a long time ago I used to take meds for bacterial infections in my stomach, I'm not saying this is the case but some may need to be checked on this too. But because my issue is TMAU related the choline foods I eat actually cause the bacteria that's why I have to cleanse my colon or use laxatives. But sometimes IBS can cause fecal odors too and anal fissure. Enzymes also helpbreak down proteins in the body that are hard to digest.
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.