To prevent vomiting after surgery, a precise, calculated dose is usually given just before or after the induction of anesthesia by a qualified practitioner [5]. Common Forms of Administration
Because it is so effective, ondansetron can mask the symptoms of more serious issues, like appendicitis or a bowel obstruction. Always consult a pediatrician if vomiting is accompanied by severe abdominal pain.
Prevention and treatment of nausea and vomiting due to gastroenteritis, postoperative causes, or chemotherapy (though dosing for chemotherapy differs and is not the focus here).