So DS3 had the stomach flu for the third time since October this weekend. Why? How is he sick so much? I need suggestions to keep him healthy and the rest of the family. He picks up some type of bug then the whole family ends up sick with it. UGH!!! I called and got a quote to have our air ducts cleaned. I know it won't help with viruses but won't it help our immune systems since we won't be breathing in all the allergens?