Daycare Dramas

Hi Ladies, was just hoping to maybe get some opinions or at least vent my confusion about my son's daycare issues.
He's 6 months old and goes to daycare 2 days a week. He started out doing great there but then when he hit 4 months he got sick with a bad reaction to his 4 month shots, and then after that he got a cold and then diarrhea so he's been absent a lot of the last 2 months from being there. Now he's well again he's back to being there 2 days a week but he is not doing well.
His carers tell me he's crying a lot, won't eat and won't go down for naps. This week on Wednesday they told me he didn't want to eat and the first bottle they tried to give him he acted like he was choking on it.
On Thursday they told he was very very fussy all day and barely ate or drank a thing.
But when I bring him home he's perfectly fine and acts normal. Eats, drinks, sleeps, and doesn't cry or fuss. I know he's teething so it could be partly because of that, but part of me is also wondering if it's separation anxiety or if he just doesn't like it there.
He gets baby sat by his Nanna 2 days a week, goes to daycare 2 days a week and is with me 3 days. He has acted completely fine at his Nanna's or with me. It's only when he's at Daycare that he's having issues.

I'm really torn about what to do about it. Has anyone else gone through a similar situation? I hate thinking he's so unhappy there so I'm considering moving him to another daycare.

Alissa may have a point with overstimulation. Does the surrounding environment seem noisier than your home or Nanna's?
    8Theresa Gould
    Everyone else has mentioned things I would have so I'm not sure. Hope you figure things out for him soon.
      I think everyone has given great advice. i do like the drop in unannouced thing ... it really lets you know what is going on!
      About Lis Outland
      Current: Selma, North Carolina
      Birth: December 31
      On since: Jan 11, 2014
      I'm the Mummy of a very beautiful little boy named Jayson. He and his daddy are my world. I'm an Aussie gal living in the USA.