respiratory disease, runny poop, not laying

[silvergranite]

We have two chooks which started laying regularly. To make it more of a flock we bought another hen of the samilar age...but didn't quarentine her (learning curve here)
It turned out we bought a sick chicken which quickly infected the other two. They have been on antibiotics and have stopped gurgling and their eyes are bright and seem to be healthy. They still are not laying properly(one not at all). They often have leathery egg shells or are sometimes rough textured. The new hen continues to have very runny clear poop. She drinks far more than the others. They have one day left to eat their deworming powder. Can the deworming have anything to do with this or have a got damaged chickens?
From what I've read it sounds like they have got Infectious bronchitis which doesn't bode well. I've included an image of the poop. Thanks

 

[Wyandottes7]

The symptoms you describe do sound like Infectious Bronchitis. Still, there are many respiratory diseases that all have very similar symptoms. Its pretty hard to find out the exact respiratory disease unless you get a necropsy. In fact, I think that Bronchitis is not as likely as a bacterial disease, since you said that the antibiotics almost cured them. Viral diseases aren't cured by antibiotics.

The watery droppings that the hen is experiencing might be because she drinks more water, or she might eat less than the other birds. Worming was a good idea, as worms can cause diarrhea, but if you haven't seen any improvement, it likely wasn't worms.