Thank you for your query.
You mention that you son has been "poorly" for several weeks. This is not clear. If he is unwell then he must have been investigated and some reason must have come out for his being pale. Following upper respiratory tract
infection and what you believed to be rotavirus
) it is natural for your son to be weak and off colour. This may be making him more sleepy and giving him the red patches under his eyes and around the mouth.
I suggest that you get your son re-evaluated by the doctor so that he can guide you further.
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.