Hello Thanks for query. You have been diagnosed to have renal stones ,Since you have repeated episodes of pain it suggests obstructive uropathy due to stone mostly impacted in ureter.and has to be dealt with immediately. Please consult qualified Urologist for proper evaluation and investigations like ultrasound scanning and to explore need for any active intervention to remove or fragment the stone .This is very important to save the kidney from being damaged due to back pressure changes (Obstructive Uropathy). .The fleshy particles that you are passing in urine are the infected debris with mucosal lining of bladder (Muck) Dr.Patil.