Mom cannot tolerate any food at all. It is too painful. This is a sign of gall bladder disease. In a normal healthy person, they would just remove the gall bladder. In mom's case, she may not be able to take the surgery.
Her kidneys and intestines also need investigating. They will do CT Scan to get clear picture of he condition. Then only can decide what is next course of action : to treat or to just put her on pain management.