If you still have severe pain on the 2nd day after lithotripsy for renal colic, you may have larger stones remaining after lithotripsy, or the stones may have cut through the urethra during expulsion. Extracorporeal Shock Wave Lithotripsy (ESWL) is a procedure that breaks up larger stones into smaller pieces, which are then expelled from the body under the impact of urine. If the stone is large, and the remaining stone is too large to be discharged, it can cause renal colic symptoms. In addition, during the process of discharging the stone, due to the angularity of the stone may cut the mucous membrane of the urethra, which can also cause pain. If you have pain on the second day after stone removal, you can apply pain relieving drugs such as diclofenac sodium and indomethacin suppositories as prescribed by your doctor, and drink plenty of fluids, and if there is still no relief, you need to be further examined and treated.