that would be typical for ascaris, and they may leave when upset by something. Keep in mind that lack of food is not the only reason (if it is a reason at all!) that they may show up in a nose or in mouth. And even then, rest assured that they've left behind plenty of eggs to hatch as soon as things are back to normal. Hence I would neither connect the lack of food with Ascaris departure, nor would I conclude from that that lack of food is a good thing when trying to get rid of parasites.