What Causes Severe Abdominal And Back Pain?
Stomach Virus and or possibly other more serious conditions
Detailed Answer:
Generally the most common cause for these symptoms is a Stomach Virus, otherwise known as Gastroenteritis. While this condition is usually not serious, and resolves within 7-10 days it can be quite uncomfortable, and treatment generally is not antibiotics (since it is not a bacterial infection) but rather patience, and serious hydration (drinking lots of water). Still, I highly suggest you make a visit to the Doctor and or Emergency Room as soon as possible. Severe pain in the stomach and back accompanied by headache and nausea can mean a variety of things; unfortunately these symptoms are present in the more serious conditions as well (Meningitis, Appendicitis, Gall-Stone issues and even Cardiac (Pericardial inflammation). If it were my daughter, I'd want to get a checkup just to ensure it was nothing that required immediate intervention.
I hope my answers have been useful for you. Please feel free to follow up with any further questions, I'd be happy to continue discussion.