<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, may I answer your health queries right now ? Please type your query here... Sir I underwent a surgery during 2002 for PUJ obstruction on right side in AIIMS, every thing went right. Now some times I feel some mild painakdan in my back during sleep in night. I also got the ultra sound and obstruction was not there.  <response>: Dear patient Since recent ultrasound and was normal you need not worry about renal calculus and obstruction. Mild back pain may be due to muscular origin. I would like to advise radiograph of lumbosacral spine anteroposterior and lateral views to be sure there is no bony pathology. Start tab diclofenac plus thiocolchicoside combination twice a day for pain relief. Do stretch of back before getting out from bed. All the best 