The horrible smell is due to the bacteria in your intestinal tract, anaerobically metabolizing the protein. Anaerobic bacteria convert protein into some of the nastiest smelling compounds...even the names give away the problem: skatole, cadaverine, putrescine, etc.
To combat the problem, you might try using the Probiotic capsules, that contain Lactobacilli and Bifidobacteria cultures, along with fructooligosaccharides. This will increase the competitive flora. Also, green tea has been shown to reduce anaerobes and increase Lactobacilli concentration.