Brief Answer:
Yes therapy with Dificid should be considered.

Detailed Answer:
Hi Dear,
Firstly thanks for choosing HealthcareMagic for your query.
I am Dr XXXXXXX a Gastroenterologist and will be addressing your query.

Have gone through all your details and answers are as follows-

1)Fidaxomicin versus vancomycin for Clostridium difficile infection-
According to Clinical Trials gov number, NCT0000.) :The rates of clinical cure after treatment with fidaxomicin were non inferior to those after treatment with vancomycin. Fidaxomicin was associated with a significantly lower rate of recurrence of C. difficile infection as compared to vancomycin.

A quote from a topic from Love and Bailey(Bible of Doctor) says-"Fidaxomicin represents an important development in the treatment of clostridium difficle infection with significant advantages over the other currently available antimicrobial agents like vancomycin and metronidazole. These advantages include lower rates of C.Difficle infection recurrence, twice-daily dosing, and minimal side effects.

"That fidaxomicin has been shown to be superior to vancomycin in preventing recurrent Clostridium difficle infection may be due to its narrow spectrum of activity allowing the gut to repopulate a normal microbiome, as well as the inhibition of C. difficile sporulation and of clostridial toxin production. Inhibition of sporulation by fidaxomicin may reduce transmission of the infection to others by reducing shedding or spores and resultant environmental contamination."

An article published in XXXXXXX college of Gastroenterology says-
"Fidaxomicin should be considered as first-line therapy for the management of CDI in patients with multiple factors cited in the literature that would place them at high risk for relapse and recurrent CDI especially in those populations that have been identified as having improved outcomes with fidaxomicin use: those receiving concomitant antibiotics, those with renal dysfunction, older individuals, and in those with treatment failures(your case).

Another study conducted on large group says-
A total of 406 patients were enrolled at Canadian sites and underwent randomization; 201 patients received fidaxomicin and 205 patients received vancomycin. Clinical response rates were similar between arms (90.0% for fidaxomicin and 92.2% for vancomycin;Fidaxomicin was associated with a lower rate of recurrence compared with vancomycin (14.4% versus 28.0%).

So all these standard trial show that both vancomycin and Fidaxomicin are almost equal in eardicating primary infection when used in optimal doses. However chances of recurrence of infection is significantly low when Dificid is used.This undoubtedly makes Fidoxomicin the drug of choice.

So yes as per your question primary therapy with Fidaxomicin along with Benzotoxumab should be used.Its the latest and most widely used regimen these days.Cipro,Vanco and Metro are usually used in developing countries for the only reason that they are cost effective

2)Should you use VSL#3-
Before answering this question let me first tell you what are probiotics?
Why are they given and how they work.

Probiotics contains lactobacillus and many other bacteria's which are good for digestion. These good bacteria's help in proper digestion of food and will help to revive your depleted gastric flora(clostridium infection plus repeated antibiotic therapy depletes the good intestinal flora".

To be more precise
Gut flora is the complex community of microorganisms that live in the digestive tracts of humans. The intestinal microflora is a complex ecosystem containing over 400 bacterial species. Anaerobes outnumber facultative anaerobes. The flora is sparse in the stomach and upper intestine, but luxuriant in the lower bowel. Conditions like bacterial infection destroys this microflora of gut and lead to various problems with digestive system including belching, bloating loose unformed stools etc.
Probiotic mechanisms of action include enhancement of the epithelial barrier, increased adhesion to intestinal mucosa, and concomitant inhibition of pathogen adhesion production of anti-microorganism substances and modulation of the immune system.In LAY MANS language it contain a lot of bacteria's which forms a part of normal gut flora,Hence it substitutes the flora lost during a pathological condition and improve overall digestion and stool formation.So yes answer is you can use VSL3 or any other standard probiotic for overall improvement of digestion.

Though not asked yet in the same way Prebiotics are undigestible food ingredients that beneficially affect the host by selectively stimulating the growth of a limited number of bacteria in the colon, thus improving digestion.Again the work is same to stimulate the growth of the bacteria's in gut flora.Hence overall both of them help restoring the lost gut flora and helps in digestion. They are definitely very good for patients in long terms.

Another suggestion is take Isapghul husk 10 gram thrice daily soaked in half cup of XXXXXXX warm water. This natural husk swells up and absorbs intestinal water leading to formation of bulky and well formed stool.
For vancomycin resistant clostridium difficle alternative treatment strategies, such as nitazoxinide, monoclonal antibodies (CD A-1 and CD B-1), IV immunoglobulin therapy and vaccination are there.

I hope i answered your query well and in detail.
Yyou are on anbtibiotoics from a long tiome.Though regiumen used by your primary was good but not the latest.
Above mentioned details should be discussed with your primary or Gastro and drugs should be switched.

In case you need any other details i would be happy to help.If possible please don't use short forms.

Regards.

---