it is realy common, but typically there are a bunch of other symptoms that follow with the vomiting.
Obviously, wait until the tests come back. The one to test for it is a bit costly, but the management, once you get the right recipe of meds can be easy to work through.
It is a frustrating disease but once you get the diagnosis, definitely read through the thread below and then ask away! We've got all kinds of info for you.viewtopic.php?f=5&t=47793
Until you get the diagnosis and see the vet again, try to keep the same routine as normal and don't let exterior stressors get to him. Sometimes it can be not keeping our own human schedules that start the cycle of illness.