Sick chicken Owner confused

[tornduff]

Alright people, I have a sick chicken and I am so confused on what it could be. Her are Glenda's symptoms: stands away from others, doesn't eat much, weight loss, drinks ALOT of water, diarrhea that is clearish to a white in color. At first I was thinking Meraks but now I'm not sure. I've been reading so much info that anything I read sounds like it could be the problem. First I thought sour crop then cocci...now I have no clue. Anyone please help!!!!! I want to be able to help her but I need to know what I'm dealing with so I know how to treat her.
I removed all hay in their coop, run and nesting boxes thinking that was the problem causing the Meraks. I did have a chicken of mine die of this disease just after a couple of months of getting her. Then I had another chicken die unexpectedly about 6 weeks after the first. Now here its is 6 weeks later from the second and I have another chicken that has symptoms that i'm no sure of. I don't even know what my second chicken died of, since it was so unexpected.

Anyone please help

 

[tornduff]

Oh and one more thing...Glenda is almost a year old started to lay eggs 3 weeks ago and stopped laying a week and a half ago.

 

[groundpecker]

The only clear way to discover what your birds have, is to get one of them tested. Treating an illness without knowing what it is, is a waste of time.

 

[tornduff]

This is Glenda(black&white) and Delaware(red)