Flu can go on a long time. Mild flu ranges from body aches, fatigue, cold chills, fevers to throwing up/diahrea etc - we have had the mild flu symptoms of body aches and fatigue ... even the bronchitis part of it is lingering longer... best thing you can do is have him or her rest as much as possible and you too - so you do not get it! Rest, lots of videos - special foods like popsicles, fun chicken noodle soup, spaghettios - gatoraide, jello - anything in the BRAT diet works great for kids sick like that. I have my standard grocery list for when our house is plagued with illness like this...those are the things we like to eat mentioned above and are tolerated and relatively inexpensive. Hang in there!