Suggest Treatment For Stomach Pain In A Child

my son who is 4 almost 5 has had stomach pain for the last 4 nights and 3 days. there has been no vomitting or diareaha. he has had normal bowel movements with the exception of today where he hasn t had any. the first night he just mentioned it and fell asleep. the next day the school teacher said his stomach had hurt. then that night he had severe stomach pain through the night. day 2 he felt weak. had a mild fever and had some stomach pains through the day. his appetite was less. he ate cherios and part of a sandwich. we gave him advil and childrens chewable pepto. (calcium carbonate) as directed. that night was again severe stomach pains between 8 pm and 1 a.m. today day 3 he felt better. ate a full breakfast of french toast and lunch was mac and cheese. by dinner he was feeling weak and had a fever around 6p.m. we gave him motrin and again chewabel pepto. by 8 p.m. his pain was coming back. i went and got him infant liquid simethicone and gave him 60 mg. at 10:30. his pain continued and he just fell asleep at 11:15. i am hoping the simehicone will help. tomorrow we plan on bringing him to the pediatrician. we are considering an e.r. visit tonight.