My 82 yr old mother suddenly started vomiting & having diarrhea Thursday nite(2.5 days ago) It lasted till middle morning the next day. Figured it was the flu. We both had eaten the same dinner, I was fine. She took Imodium as her bowels would release without warning. She felt very lethargic. Seemed better on Saturday except weak. Slowly added fluids & ate a little plain rice. Went to bed at 9pm, up at 5 am. It s now 2:00pm she is headachy, body aches, especially her back, very weak ate a small potion of mash potatoes . Has kept it down. Took 2 alleve for her back which has begun to hurt again. She took to her bed which is not like her. She usually sleeps in her chair. Usually a very active woman, takes only blood pressure meds and sees her doc regularly. She s 5 1 138lbs. Now 132 lbs. is it the flu? How long do these things last? Had a flu shot beginning of No .