Hi there. Vanco is the antibiotic used to kill c-diff when flagyl alone does not work. It is very expensive. Depending on where you live, it can range from $750 to $2000 for a 10 day course. It works very well. I used it last year at this time in conjunction with Flagyl. Because flagyl has always made me sick, I cannot tell you if using Vanco alone would also make you feel nauseous. I was extremely ill with the c-diff and spent 6 nights in hospital, and an additional month of home health care hooking me up to IVs every few days. I went through 3 different rounds of that combination to get rid of the c-diff. I was off work and the cure took 3 months but was well worth the daily nausea. If you haven't started Vanco yet, and flagyl did not resolve your c-diff infection, by all means I recommend you do the Vanco, before you are damaged so bad that they start removing portions or all of your intestines.
A bit of info about vanco being used to treat UC. It is used in the treatment of UC CAUSED BY by C-diff. Severe cases of c-diff cause UC. Mild cases may just cause severe bowel distress, without causing UC. If you do not test positive for c-diff, your practitioner most likely would not perscribe vanco to solve UC.
I wish you luck on getting cleared up.