URS is a type of treatment which is done using a small caliber endoscope that is passed through the urethra without making an incision in your body. The stone is pulled out by basket or fragmented by laser. In RIRS, or Retrograde Intrarenal Surgery, a flexible fine endoscope is passed into the kidney through natural opening and then the stones are fragmented under direct vision using laser. Stone clearance rate is very high, complications are minimal & patient is discharged within 24 hrs. Also, it is very expensive & not suited for all types of stones. More than 300 RIRS have been performed at our hospital during the last 8 years.