Look up recent articles about the use of a relatively new procedure called fecal transplant. This treatment restores the flora balance of the intestines and seems to be effective in the literature as a treatment for clostridium differens conditions of the intestines.
Clostridium Differens is difficult to remove altogether as it forms very hard to kill spores and the procedure may have to be repeated multiple times but it will,probably provide relief.

C differens is very transmissible between people and good hygiene is very important, especially in the bathroom.