Worried about this. Help please..
 

Yesterday morning when I let Gus out he had diarrhea. It wasn't too bad. But throughout the day it got a little worse. I figured he just ate something he shouldnt have (maybe people food-wise) but I didn't worry too much cause he seemed like his normal self. But this morning it got weirder. He skipped his meal last night and this morning. He won't even touch it. And he's kind of lethargic today and he still has diarrhea. But when I was watching him I noticed he is eating his own poo now? He's 17 months. Also, he's kind of whining too..

Is this something I should worry about? Do I need to take him to the vet immediately (I'm at work now)

Go to the Vet - better safe than sorry!!!
At the very least call the Vet and speak to them, tell them his symptoms and ask if they feel they should see him straight away or if you could wait till this afternoon.
Could he have eaten a cooked bone or something?

Ditto the vet, also ditto better safe than sorry

is he drinking water ?

Not like he usually does. I put out a fresh bowl and he took maybe 2-3 laps and walked away. Usually he drinks a whole bowl.

I did get him to eat half a treat though.

He really doesn't sound well - please get him checked out!

He was outside when I was writing the last things. I went to get him cause he was barking. He bolted in the door and drank a hunch of water... and he doesn't seem lethargic now.

This is confusing.

A vet should STILL see him in order to be safe and sure that nothing is going to go wrong during the middle of the night.

I'm waiting on blood results as we speak.