Disclosed are methods and compositions for reducing toxicity associated with infection by Clostridium difficile by inhibiting Clostridium difficile toxin B (TcdB) and/or toxin A (TcdA). Such compounds include ebselen compounds, namely ebselen and its salts, ebselen functional analogues and ebselen structural analogues, as well as certain amide derivatives. This includes Formula I, e.g. 1-methyl-3-phenylpropylamine, Formula II, e.g., 2,2′-diselane-1,2-diylbis[N-(2,4-difluorophenyl)benzamide]; and Formula III, e.g. 2-(2-methoxy-5-methylphenyl)-1, 2-benzoselenazol-3-one. The present compositions may be comprised in a colon-retentive formulation that increases residence of and/or release of the compound in the area where the infection is active.