Thanks for your question on Health Care Magic. I can understand your situation and problem. In my opinion, you are mostly having drug induced gastritis. Pain due to renal stone often needs higher painkillers. These painkillers are known to cause hyperacidity and gastritis. And this is the likely cause for your middle chest pain. So better to take proton pump inhibitors. Avoid unnecessary use of painkillers. Drink plenty of fluids orally. Avoid stress and tension. Avoid hot and spicy food. Avoid junk food. Avoid large meals. Don t worry, you will mostly improve with all these. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.