My daughter's GI opted for Entocort, which has put her into remission. When she tried to go off the Entocort, she flared...Cipro was given to try to stop the flare, but instead caused a high fever.
Soon after she started the Entocort, her colonoscopy results indicated possible C Diff (she didn't have D, so we're not sure she had it) so she went on Flagyl while on the Entocort. The two together caused oral thrush. Flagyl also caused cramps, unclear thinking, extreme fatigue.
So for her, the antibiotics didn't work and caused side effects.