Hi Welcome to HCM. Hepatitis A to be ruled out first. Because of its safety concerns Ondem should not be given to a child younger than 4 years old until other wise the vomiting is caused by cancer chemotherapy or radiation. Following side effects are commonly seen with the use of Ondem: Headache, lightheadedness, dizziness, drowsiness, tiredness, yellowish discoloration of the skin and eyes (jaundice) or constipation may occur rapid or irregular heart beats, or allergic reaction (urticaria, swelling on the face lips and mouth). My advice is discontinue Ondem, consult the treating pediatrician to rule out other causes of yellowish urine like viral hepatitis A, for continued vomiting she may be given Domperidone syrup. Hope I could answer your query. Best regards.