Treating a child’s vomiting and diarrhea with flat ginger ale or cola—or lemonade—actually makes it worse, according to the British National Institute for Health and Clinical Excellence, adding that they should be treated with rehydration drinks instead. Half of all children under five will develop vomiting and diarrhea over the course of a year, reports the BBC, noting that up to one-fifth will see a health professional, and another 40,000 will go to hospital due to complications from dehydration. Serious cases could be avoided if parents and doctors followed their advice, they say. “The idea that flat coke and lemonade—or fruit juices for that matter—helps is just a myth. In fact, it can make it worse, but unfortunately people are still using them,” said consultant pediatric gastronenterologist Dr. Stephen Murphy, who chaired the panel responsible for the guidance. “Severe cases of diarrhea and vomiting leading to dehydration need treating with oral rehydration solution immediately.” Rehydration drinks have a crucial combination of sugar and salt that help the body absorb fluids, he notes, while pop and lemonade have too much sugar.