Foul breath and unusually foul BM are almost always a sign of excess yeast and/or e-coli in the gut. Yeast can be very hard to treat, and can require a long commitment to diet change. Excess e-coli is a little easier, but just as important. You might want to talk to a doctor (or even a DAN doctor) about each, since they are such complex problems. Remember that when you first start treating the yeast, the symptoms might get worse for a while, because as the yeast dies, it releases toxins. Yeast in the gut causes an array of symptoms, and some are worse than you might expect. If you are reading around, you might want to try the first two chapters of "Children with Starving Brains" by Jacqualyn McCandless. She talks in great length about yeast infections. I think there is an interview with her on the main page of this website.
