My five year old daughter was hospitalized with a UTI at 6 weeks. After many tests, including a VCUG and Renal Sonogram, she was diagnosed with Urinary Reflux. Her ureters were not strong enough to keep the urine from flowing back up into the kidneys from the bladder, which can cause infections. We finally went home 10 days later, due to the infection going septic and getting into the blood stream, with Ally on nightly lose dose Bactrim (antibiotic) and precautions to be extra careful with wiping her bottom and such.
We were seen in the hospital by Dr. Walter Snodgrass, he works out of Plano Presby and Dallas Childrens, and kept seeing him follow-ups. He is very good with the kids and willing to talk with you until all of your questions have been answered to your satisfaction.
UR can sometimes resolve itself. The only real way to test for it is with a VCUG (they catheterize the bladder then inject a substance in to watch the flow of urine). Ally's UR just didn't seem to want to go away and it was getting more and more traumatic to have her annual VCUG done, so two years ago when she was about 3 1/2 we had what is called a Deflux procedure performed. Very simply put, they injected a sugar type substance at the end of each ureter to form a bulge or flap. The bulge allows urine out but not back in. 3 months later after one last follow up VCUG we got the news that she was reflux free. To todays date, no more infections knock on wood. Hopefully this is not what is going on with your daughter, but I wanted to pass on that I understand how scary this can be and that there are ways to resolve it. Please feel free to email me if you have any other questions.