Just ask him how he felt, see if he felt better in the evening, sound concerned.

If he says he had the shits all day and night, fucking tell him!

if he's been with you for less than 2 years, I think, you can sack him without reason.

I don't pay my staff for sick days, and they better bloody answer thier home phone if they say they are off.

bloody skivers, make my blood boil....