I have recurrence of uti just finish with my antibiotic i still see like particle in my urine like foam and my back and side hurt should i ask for a culture i'm always constipated what can this be .

Yes: If you have just finished Cephalexin and still have symptoms of uti, a culture is indicated. Constipation is caused by diet and dehydration. Drink 10+ cups of water daily and eat large portions of whole foods with each meal; 3-4 fruits (apple a day) + whole grain cereal/bread. A large salad using something other than iceberg lettuce and lots of legumes (beans). Then walk 1+ miles a day.

Urine culture: Is needed to identify the infectious agent. Some bacteria are resistant to commonly used antibiotics and that may explain the recurrence of symptoms. A urine culture will help guide the antibiotic therapy.