C-diif has to be treated with appropriate antibiotics after stool culture and by doctor's decision.
ONLY (!!) together with antibiotics, you can use probiotics, containing Lactobacillus GG and Bifidobacterium bifidum. Probiotics themselves probably won't help.
Afgter taking 10 days of antibiotics for c. diff my gastroenterologist advised me to use a product called Florastor to prevent a relapse of c. diff. It's been 18 months and no relapses. You can get Florastor online or as a special order through your local pharmacist. It's expensive, but was worth it to me.