Gallstones will make you feel nauseated. Are you now eating fatty foods? Gallstones may form when you diet, but you dont feel ill until later, when you eat fatty foods again. Thats what happened to me. The only thing that makes me feel better is Tagamet or the generic for it, cimetidine. I would feel very hot and sickly. I didnt not have gall bladder surgery, i just refrain from eating fatty foods.