Tired chick w watery poop

[jdgbirds31]

I have a 10 week old chicken that has been seeming rather tired the last 2 days. Not lethargic constantly, but napping more than the others and put herself to bed for the night an hour early. Also her poops are basically just water. She sits a little puffed with her bum kind of in the air and when I saw her poop she looked very unhappy about it. Seems to still be eating and drinking, I checked for mites, etc., and there's no other problems. Any ideas would be so helpful!

 

[jdgbirds31]

Oh and sometimes she isn't napping she is just standing there kind of puffed w her bum up looking uncomfortable.

 

[jdgbirds31]

Any thoughts? The first thing I thought was cocci, but there's no bloody poop. Not sure if that rules it out...