My son hurts in this stomach when he eats certain foods what could it be?

Pain in stomach eati. You did not say how old your son is.If he is having pains in his somach everytime he eats then he needs to consult a gastroenteriologist to rule out peptic ulcer in his stomach or other causes.We need full history, his growth graph and complete physical exam and blood test and possibly endoscopy as well.So consult your doctor.