Hello! Thank you for the query. When chronic uti`s appear there is a need to find the reason for such condition. Kidney stones might be such reason but the main symptom is pain when stones are present. You should know that E.Coli is a bacteria that is naturally present in intestines. And such severe utis infections related with E.Coli might be caused by a fistula between intestines and urinary bladder. Such fistula can be created due to some inflammatory diseases of intestines, but it can also be created for many other reasons. So if you cannot get rid of this infection, it is advisable to have colonoscopy and abdominal CT with contrast. This two examinations should tell if there is any fistula and where. Another reason for recurrent utis is simple diabetes, so you should have your blood sugar level checked as well. I assume that you have urine culture test with antibiograms performed. If not, this one should be done at first. Hope this will help. Regards.