<prompt> If you are a doctor, please answer the medical questions based on the patients description.I just recently had a really bad uti and possible kidney stones the i passed on my own at home. It has been 2 weeks gone and now it back again. I did the at home uit test and it came back leukocytes positive and nitrite negative butvis really painful again. What can be the cause??  <response>: Hello! Welcome to Chat Doctor ! I understand your concern. Some causes of UTI can be: 1 E. Coli from gastrointestinal tract.2 Sexual intercourse.3 Women may be especially prone to Otis because they have shorter urethrae, which allow bacteria quick access to the bladder. Some advice that I can give you are: 1 Try cranberries. Cranberries may contain an ingredient that stops bacteria from attaching to the walls of the urinary tract.2 Chat Doctor. 3 Urinate when you need to.4 Take prescribed antibiotics. Hope that clarifies your concerns. Thank you for the query. Take care 