My DS who turned 1 a couple of weeks ago has al...

My DS who turned 1 a couple of weeks ago has all of a sudden gone off all of his food and won't drink his milk either. We thought it might have to do with the fact we were on holidays and his routine has been disrupted but we have been home for a week and he still will eat very little and will only drink about a quarter of the amount of milk he used to. Has anyone elses kids gone through this, is it just a phase? I have a doc appt this week for his 1 yr old needles and I am going to query it with the Dr. but they do tend to put things down to "it's just a stage/phase"