Just an FYI, I had stomach/intestinal problems and was seeing a gastroenterologist regularly before being put on prednisone for PMR and was tested for SIBO before prednisone as well as during prednisone, and both were negative. On prednisone my WBC was always running around 11 - 12,000 but it wasn't until I went to the ER after 12 hours of vomiting and diarrhea that I was admitted with an intestinal infection and stomach virus with a WBC over 15,000 and was put on two strong IV antibiotics and potassium and discharged 3 days later.

So my point being is that I don't find SIBO tests as reliable. If you can, look back to old labs before you were put on prednisone to find your WBC baseline and then look at you most recent WBC blood test to see if there is a difference, and if so, by how much.