Usually, dogs with bilious vomiting syndrome exhibit normal values for blood and urine tests, but X-rays or ultrasounds may demonstrate reduced gastrointestinal motility. (cuteness.com)
Or if your child ends up with a stomach virus with vomiting every month, then maybe he has something like cyclic vomiting syndrome. (verywell.com)
He has struggled with food allergies and Cyclical Vomiting Syndrome (CVS). (tessadomesticdiva.com)