You have a local anaesthetic (where you're awake) or a general anaesthetic (where you're asleep), so you should not feel any pain. Bladder Stones - StatPearls - NCBI Bookshelf

Bladder stones are rarely a primary condition; they are usually a symptom of an underlying issue that prevents the bladder from emptying completely: Bladder stones - NHS

(also called bladder calculi ) are hard mineral masses that form in the urinary bladder. They typically develop when urine becomes highly concentrated, causing minerals like calcium or magnesium to crystallize and clump together. Common Causes