Every year millions of children worldwide get an episode of gastroenteritis. Gastroenteritis is caused by one of several germs. It is characterized by vomiting and/or diarrhea. Our gut has a lot of bacteria in it. Probiotics are members of gut bacteria that are believed to be healthy. They are a single bacteria taken out of the gut and grown up in a flask and then washed and put into packages and sold as probiotics. For years people have been giving probiotics to children with gastroenteritis in the hopes that it could shorten their illness or make their symptoms better. Dr. David Schnadower asked a simple question: If children come into our emergency department with gastroenteritis and receive a probiotic or are randomized to receive a placebo, do the children who receive the probiotic get better any quicker. And the answer, after enrolling nearly 1,000 children over several years at multiple sites in the United States, the answer was a resounding no. That the children who received the probiotic got better at the exact same rate as the children who received the placebo. So my recommendation to a family would be that a probiotic in a setting like this is probably harmless, but it is certainly not going to shorten the illness. I would recommend that they not spend their money on it and save that money, the child gets better, and invest it in fresh fruits and vegetables.