My nephew is 4, he s been having a fever off and on since Saturday. He went to the ER, they said he had pneumonia , gave him antibiotic , and sent him home. They lowered his fever from over 103. He started vomiting while going to get prescription. The next day, his fever was back, and he was still vomitting. They took him back to ER and they were told he did not have pneumonia, and the dr,took the medication away. They said he had the flu . His fever was about 102, they dropped the temp before releasing him. Today, Monday, his temp is at 102.3, and he s still vomitting. He hasn t ate anything, anything he drinks, he vomits it up. What can be the problem?