Baby Chick Retaining Water in Bottom??

[Hannahonfire17]

We have a baby chick we are keeping in our house.
It was actually an abandoned egg the mom stopped sitting on when three others hatched.
My mom and sister found two dead ones, but one still alive.
So we put it in our incubator a few days.
Well, it looked to be getting shrink wrapped after a few days, so I initiated an emergency egg C-section.
It was a little messy, but he seemed in good health.
Moving around and peeping a lot.
It did still kinda have a lot of the umbilical cord thing attached with a little bit of yolk.
He smelled bad for a long time! Gave him like 3 baths.
He seemed fine up until recently.
He poops often, but they are tiny and thin and dry.
He peeps a LOT. Which is pretty normal to an extent I guess.
Then today I noticed that not his vent, but below his vent it seems swollen.
There's a spot thats even a little bald from how its kinda poking out.
I pushed on it and it feels like water! And it really worries me
Is there anything we could possibly do do drain it or to get his system back into wack?
Soaking him in some warm water maybe?
Any kind of food? Medicine?

 

[sumi]

Does it look anything like this:

https://www.backyardchickens.com/a/mushy-chick-disease-yolk-sack-infection-omphalitis

(Warning: graphic pics in article.)

 

[Hannahonfire17]

Yes, a little like that.
Were thinking it probably is some kind of infection.
Good news is its still really perky and in good spirits.