The intestinal flora may play a key role in the pathogenesis of certain gastrointestinal (GI) diseases. Components of bowel flora such as Lactobacillus acidophilus and Bifidobacterium bifidus have long been used empirically as therapeutic agents for GI disorders. More complex combinations of probiotics for therapeutic bacteriotherapy have also recently become available, however the most elaborate mix of human-derived probiotic bacteria is, by definition, the entire fecal flora. Fecal bacteriotherapy uses the complete normal human flora as a therapeutic probiotic mixture of living organisms. This type of bacteriotherapy has a longstanding history in animal health and has been used sporadically against chronic infections of the bowel, especially as a treatment of last resort for patients with severe Clostridium difficile syndromes including recurrent diarrhea, colitis, and pseudomembranous colitis. Encouraging results have also been observed following infusions of human fecal flora in patients with inflammatory bowel disease, irritable bowel syndrome, and chronic constipation. The therapeutic use of fecal bacteriotherapy is reviewed here and possible mechanisms of action and potential applications explored. Published reports on fecal bacteriotherapy are few in number, and detail the results of small uncontrolled open studies and case reports. Nevertheless, given the promising clinical responses, formal research into fecal bacteriotherapy is now warranted.