I had a foul smelling "thick fluid" which came from sores in the groin area - the skin had turned raw and was becoming an open wound - I believe it was called jock itch. I would notice it everytime I went toilet, sometimes on hot days I could smell it when I was standing still. Tried most antiseptics and could never get shut of it completely, after a week or so it would come back.
Do you get itchy skin? thats another sign.
Since I have been aware of it I have cut down on Sugar
and cheese and it has gone - no more smell.