bladder infection
"Started nifurantoin on Friday. After fifth dose started headache, chills, flu like symptoms. Then severe low back pain and I thought, this moved to my kidneys. Took two more doses and went to my Dr. on Monday with insane low back pain, and joint pain down my body. I thought maybe I had the flu. When I told the nurse my symptoms she said "it's the medication, your urine shows no infection now. "  Dr. confirmed and changed the medicine after telling me her patients that react this way look and feel like they have the flu. Today is day five and I still have bad low back pain. I wonder how long it will last because it's horrible. Dr's should warn their patients."