What Causes Stomach Pain And Recurring Diarrhea With Normal X-ray In Children?

My son started vomiting last night at approx 130am....He is 6...He also had severe diarrhea like that sounded like he was peeing...All liquid....have been giving him pedilyte..has low grade fever of 99.3 under arm...has severe dark circles under his eyes and is complaining his stomach hurt....diarrhea stopped but can t keep anything down....He had a virus about two weeks ago...no diarrhea then...at a loss have had stomach X rays about a month ago done nothing out of ordinary..He always complains of stomach hurting