Hello, My son immune system is very weak. Whenever there is a change of weather, he would easily get the flu. It is accompanied by pain in the stomach especially if he s active e.g walking. When we bring him to a doctor, they will just give him medication for his cough and some antibiotics. My question is, is it normal for him to have stomach pain whenever he have the flu? If not, what are the possible condition or sickness it indicates? Thank you.