Before culture on selective media for C. diff. I would recommend you to do "alcohol shock" treatment of stool sample (1:1 with 70% methyl alcohol for 30-60 min, room temperature). Then you can inoculate this stool sample (2 drops) directly on CCFA agar (e.g. BRAZIER'S CLOSTRIDIUM DIFFICILE SELECTIVE AGAR ) as was suggested by Dr. Zimmermann as the second step for subculture of C. difficile isolate.
You will save money and time. Chromogenic agar works without "alcohol-shock" but DNA from colonies is not suficient for molecular typing.
If you are planning to grow laboratory C.diff strain, you can use brain heart infusion broth (from BD) at 37 degree in anaerobic chamber. I had a lot of success growing strains from ATCC and clinical isolates.