However the common ones are gastritis or peptic ulcers,gastroenteritis(irritation
and infection of the digestive tract.),gall bladder disease,liver pathologies,
migraine,GI diseases and neurological diseases.
Are there any other symptoms like fever,abdominal pain,headache,dizziness etc?If you could elaborate more on the symptoms that your little sister is having then it can help me more in making a diagnosis.