Hello, Kidney stone removal surgery or lithotripsy do not cause the bad taste and smell symptoms that you are experiencing. During surgery, anesthesia is given and that can cause you anosmia, ageusia, hypogeusia, dysgeusia, and thereby rotten egg smell, etc. Sometimes patients experience dry mouth (xerostomia), during stress and dehydration. It can be due to that. If a person has history of sinus infection or oral thrush, his symptoms can be triggered during the procedure and hence get bad taste or smell. Helicobacter pylori can also alter taste and smell. You are advised to get clinically examined by your treating doctor to rule out underlying health conditions that may be causing you symptoms. You will be treated accordingly. In the meantime, Drink adequate amount of water and fluids as this will avoid dehydration. Take proton pump inhibitor (PPI) pantoprazole, to reduce stomach acid production. Acid reflux, GERD also causes change in taste. Helicobacter pylori cause metallic taste. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician