Penicillen symptoms and conditions

I was prescribed Omnicef for Strep throat and an ear infection. I have had strep throat several times in the past but this was my first time taking Omnicef. Besides not feeling better until about the 5th day of taking it, I got severe diarrhea and nausea. I contacted the doctor and he told me to "stick with it" and he was confident it would make me better. Two days after finishing every last pill the strep throat was back. I would never recommend this antibiotic to anyone and I refuse to ever take it again. I am now on Penicillen and began feeling better immediatly.