Symptoms of appendicitis come on all of a sudden? Friday picked up from school she seemed loopy, talking constantly, like slurry. Unlike herself. Sat AM abdominal pain rubbing middle of stomach. Ate a piece of toast, still had pain vomited 1 hour later. She slept for 2 hours had slight fever, still pain. ate some food, two hours later, vomited. Not much sleep at this point. we bought soup, pedialyte, and tylenol cold and flu, Sunday daytime, gave some to her. She was better. Next dose, takes fever down, but pain on right lower side of stomach is bad. she cannot walk well, she had some soup, Stomach is painful to the touch. Sitting on floor leaning forward on bed seems to be the only comfortable position. It is now Sunday night, Flu is going around town, but this seems different.