C. Diff or IBD?

This all started the end of September when I developed a rash later identified as erythema multiforme (can be a manifestation of Crohn's). In trying to get it diagnosed and treated, was put on a broad spectrum antibiotic followed be a z-pack. While on the z-pack, had extremely painful bowel movements with some blood on the stool and wiped. My PCP suspected hemorrhoids and/or a fissure though I had no recent history of constipation, etc.

Later that week, had a few bouts of urgent diarrhea and then for the days following several loose bowel movements a day which was totally out of ordinary for me. Went to my PCP, got a stool sample done, and was told I was positive for C. diff. Took 10 days of flagyl, never really felt much better, and relapsed 5 days later. Was put on 10 days of vanco which by day 8 felt almost entirely normal and felt much the same until I relapsed again 10 days later and now on a 10 day course of Dificid.

My concern right now is that it seems at least one, if not all, of my C. diff tests show that I am positive for the antigen but not necessarily the toxins. This might mean that I am a carrier and my symptoms are something else entirely. Saw a GI last Monday and she wants to see how I feel on the Dificid and if I don't show improvement have a colonoscopy done.

She ran blood work that showed my WBC was normal as well as my hemoglobin, etc. Also tested negative for celiac disease.

Guess my questions are this, if I have Crohn's or UC, would I have felt better on the vanco? My current symptoms are anywhere from 1-12 loose stools a day, some mucus, middle back pain, bloating, excess gas, pressure/fullness from my rectum, incomplete bowel movements, and a very grumbling stomach. Don't have any real abdominal pain and have not had blood since the initial instance. Are there any other tests aside from a colonoscopy to provide answers? Worried about cleaning out my system as I have been working hard to try and replace some good bacteria since being on all of these antibiotics.

Already taking florastar and drinking kefir daily. Dificid is specially designed to only attack C. diff so it should be leaving the rest of my gut bacteria alone.

Would a CT Scan or MRI show anything? Rather do that before a colonoscopy.

Thank you. My GI wants me to call her today with an update on how I'm feeling on dificid so will ask why she wants to do the colonoscopy and when. Scared it will wipe out all the probiotics, kefir, etc. but guess it might be something that I can't avoid.