i am worried about my son all he does is complain about his stomach hurting  and every so often he complains of his butt hurting as well. this did not start until he first started school and he first got strep and they started him on antibiotics back in august.
I presume he is about 5-6 years old. Is there any element of coercion in making him eat his food? Are either of you among the parents forcing him to eat food against his wish? If you are, then that is the cause of his symptoms and not some gastric illness. I don't think this problem is at all related to the school event that you described, or to the use of antibiotics. The butt pain could be due to some injectables given to him in his butt area. If not due to that, you should get him checked by his pediatrician.