are you sure the faecal stench is coming from the body and not the breath :-/?
It's common for ppl who suffer from chronic bad breath to produce all sorts of faecal stenches. The stench can also affect the sinuses and our sense of smell, so that we can be tricked to think the body stinks, when it's really just the nasal/oral area. It can be extremely confusing. Can you smell it yourself, or do you go by comments from others? If you can smell it yourself... where is the source..?
A good breath group below, btw, *if* you think you have a breath prob: