It may also be given rectally if the person develops an ileus.Fidaxomicin is tolerated as well as vancomycin, and may have a lower risk of recurrence. Fidaxomicin has been found to be as effective as vancomycin in those with mild to moderate disease, and it may be better than vancomycin in those with severe disease. Fidaxomicin may be used in those who have recurrent infections and have not responded to other antibiotics. Metronidazole (500 mg 3 times daily for 10 days) by mouth is recommended as an alternative treatment only for C. difficile infections when the affected person is allergic to first-line treatments, is unable to tolerate them, or has financial difficulties preventing them from accessing them. In fulminant disease vancomycin by mouth and intravenous metronidazole are commonly used together.Medications used to slow or stop diarrhea, such as loperamide, may only be used after initiating the treatment.Cholestyramine, an ion-exchange resin, is effective in binding both toxin A and B, slowing bowel motility, and helping prevent dehydration. Cholestyramine is recommended with vancomycin. A last-resort treatment in those who are immunosuppressed is intravenous immunoglobulin. Monoclonal antibodies against C. difficile toxin A and C. difficile toxin B are approved to prevent recurrence of C. difficile infection including bezlotoxumab. Probiotics
Evidence to support the use of probiotics in the treatment of active disease is insufficient. Researchers have recently begun taking a mechanical approach to fecal-derived products. It is known that certain microbes with 7α-dehydroxylase activity can metabolize primary to secondary bile acids, which inhibit C. difficile.
Cytotoxicity assay
C. difficile toxins have a cytopathic effect in cell culture, and neutralization of any effect observed with specific antisera is the practical gold standard for studies investigating new CDI diagnostic techniques. Toxigenic culture, in which organisms are cultured on selective media and tested for toxin production, remains the gold standard and is the most sensitive and specific test, although it is slow and labor-intensive. Toxin ELISA
Assessment of the A and B toxins by enzyme-linked immunosorbent assay (ELISA) for toxin A or B (or both) has a sensitivity of 63–99% and a specificity of 93–100%.Previously, experts recommended sending as many as three stool samples to rule out disease if initial tests are negative, but evidence suggests repeated testing during the same episode of diarrhea is of limited value and should be discouraged. C. difficile toxin should clear from the stool of somebody previously infected if treatment is effective. Many hospitals only test for the prevalent toxin A. Strains that express only the B toxin are now present in many hospitals, however, so testing for both toxins should occur. Not testing for both may contribute to a delay in obtaining laboratory results, which is often the cause of prolonged illness and poor outcomes. Other stool tests
Stool leukocyte measurements and stool lactoferrin levels also have been proposed as diagnostic tests, but may have limited diagnostic accuracy. PCR
Testing of stool samples by real-time polymerase chain reaction is able to detect C. difficile about 93% of the time and when positive is incorrectly positive about 3% of the time.