Does anyone know if it is possible for a c-diff infection to be misdiagnosed as UC.
Yes, absolutely. Any doc that doesn't test for c-diff when you present with colitis type symptoms is a quack IMO.
Colitis caused by c-diff is called pseudomembranous colitis.
See here: www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001305/
My wife says that flagyl (metronidazole) or vancomycin are the current treatments of choice for c-diff. Failing that, fecal transplantation is the next step.