Hello and welcome to HCM. Thank you for your query. I would like to first comment on the 4mm stone that you have in your renal system. As this is of size 4mm, it could easily be the cause for all your problems. With the advancement in medicine, this stone can and should be removed without causing you much trouble. Instead of treating the UTI every time it occurs, why don t you just treat the cause, which is the stone. Having the stone removed can be a simple procedure, and there are many you can choose from. Obviously, your doctor will suggest the best technique depending on the size and location of the stone. Once, the stone is removed, your problem will be permanently solved. I hope you understand this. Now coming to the pain while urinating and other symptoms of a UTI, you have been experiencing. A stone can cause obstruction in the normal flow of urine, this stagnation of urine can lead to accumulation of bacteria and thus, an infection. You most probably do have an infection, and will require treatment with antibiotics, pain management medication and a urine alkalizer (if your urine is acidic). For now, unfortunately the only thing you can do is to consume plenty of water, cranberry juice and add baking soda to your water. These home remedies are not to be mistaken for treatment options, but will only help in releiving your symptoms to a certain extent. Mainstay of treatment is antibiotic therapy. I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you. Best wishes.