One thing you may want to try is cranberry pills. The juice has too much sugar in it, so the sugar kinda wipes out the benefits of the cranberries. The 24 hr. urine test, although a pain to do, will tell the doctors a lot. So you should get some answers.
also have they ever did a ct scan to check and see if you possibly have kidney stones?
also the ecoli is usually from when you wiped or can be transmitted through sexual activity