Hi, thanks for using HCM. Hiccup is generally a harmless symptoms. However occasionally this can be an indication of something wrong and abnormal going on inside the body. The cause of persistent hiccups needs to be found than treating it. Since your son has continuous hiccup going on for a day, we need to rule out pathologies like infection, electrolyte and metabolic abnormalities - hyponatremia, thyroid disturbance, renal and liver disturbances and neurological dysfunctions. Therefore if he was to be my patients, I would order battery of tests that includes complete hemogram, serum electrolytes, renal function, liver function to start with. I would also write a prescription for antacid, prokinetic drugs (metoclopramide) and dopamine antagonist (chlorpromazine) to stop hiccups. Hope this helps you. Regards