What Causes Vomiting And Being Diagnosed With Functional Abdominal Pain?

My daughter got sick about 2 weeks ago. Original symptoms were flu-like, absent a fever. The sore throat went away, but she continues to have headache, stomachache, muscle pain and exhaustion. She tested negative for mono. We are headed back to the doctor tomorrow for a third visit.My younger daughter had something similar about six months ago, but it was more stomach-focused and included vomiting. It lasted three months, then went away. We went through all kinds of tests, and ended up with an unsatisfactory diagnosis of Functional Abdominal Pain. Is there some new disease out there that the PCPs aren t picking up on?