Hi welcome to Health care magic forum.
Your son is suffering with fever, few motions, stomach bloated, and not feeling hungry. It appears to be Enteric fever
, or may be any fever. any fever can show the same symptoms, besides its typical symptoms.
As it is multi symptom fever i advise you to consult a doctor for diagnosis and treatment. You may need to go for blood tests foe confermation of the diagnosis.
Don't worry he will be fine with minimum treatment.
Wishing him a quick recovery and thanks for calling.