Sinusitis
"After four days on Cefdinir, I developed bad diarrhea that had me going 30+ times to the bathroom. Went to the doctor to find out I had developed a severe case of C. Diff. I was very weak, lost 10 pounds in a week and as pale as can be.  Metronidazole was the first medicine we tried, three times a day for 10 days. It seemed to work until five days after the prescription was finished. So then I went back to the doctor and got Vancomycin which finally cured it. Overall, I had to miss almost a month of school and took a while to feel normal again. I was told once you get C. Diff you are more prone to getting it again. Always take a probiotic when prescribed an antibiotic to replenish the lost bacteria!"