DS (7) still not recovered after a a bug. Should I be worried?

[zen1]

Don't know what I am asking really, but does anyone know if it is normal for DCs to take several days to recover after a bug. He has looked pale for a while, but still good energy levels, running around etc. Last Friday, went to soft play and then played in the garden all afternoon with a friend. Saturday, woke up looking very white, dark circles under his eyes and not wanting to eat. He was sick once on Saturday evening and had a bit of diarrhoea, but not a major stomach bug or anything. Saturday, Sunday and Monday he kept falling asleep in the day, not eating etc. Tuesday, Wednesday and today, he has not slept in the day, but has still not been running around (usually he is very active). Has been sitting down for most of the time, playing on the computer, watching tv. His appetite is still not great either, although he is eating.

My parents came up today (they last saw him about a month ago), and commented on his listlessness. My dad later phoned me and said that if he was me he would be taking him for blood tests, which freaked me out a bit. I did take him to the GP on Monday and he did a full examination, said there were no signs of anaemia and that there were no glands up. He also
said that there were no indications for doing blood tests and that it was probably "post viral tiredness". I am sitting here worrying there is something seirously wrong.

[zen1]

seriously