Usually not weeks, but certainly there were days Myles seemed fine. I remember the day he was scheduled for his Upper GI I almost cancelled because he hadn’t thrown up for three days and he was eating better. Sure enough the day of his test he threw up constantly (after we were home) and things just went down hill from there, so I’m glad I didn’t cancel.
I guess you have to use your own judgment. Has he been eating well, sleeping well, and been happy for weeks?
Is he on any meds?