One Hen has bigger bottom than others...

[Tookie]

No I didn't unfortunately.

Did the sack thingy look like pus at all? Or just all blood?

 

[The Chick Addict]

Did the sack thingy look like pus at all? Or just all blood?

No it was yolk for sure with some blood.

 

[The Chick Addict]

When I first saw it, I thought it was some internal organ, which sort of freaked me out!

 

[Tookie]

No it was yolk for sure with some blood.

Hmm, not sure what it is then!

When I first saw it, I thought it was some internal organ, which sort of freaked me out!

I bet!

 

[The Chick Addict]

Hmm, not sure what it is then!

I bet!

So, would it be a lash egg?

 

[Tookie]

So, would it be a lash egg?

By the sounds of it, no.
Search up "Lash eggs", and you'll see what they look like.

 

[The Chick Addict]

It looks a lot like this lash egg, but with more blood in the yolk. https://www.backyardchickens.com/threads/what-is-this-practice-wind-egg-lash-egg.914077/

 

[Tookie]

It looks a lot like this lash egg, but with more blood in the yolk. https://www.backyardchickens.com/threads/what-is-this-practice-wind-egg-lash-egg.914077/

Any ideas @Wyorp Rock , @Eggcessive , and @azygous ?

 

[azygous]

Chickens like to throw little surprises our way from time to time to see if we're paying attention. Of course we notice when something is slightly off normal, but one single thing will make it into something we should be concerned about, and that one thing is behavior.

If you see a bloody yolk, if behavior is normal, then chalk it up to a broken blood vessel. If you notice a fatty deposit below the vent, if behavior is normal, the hen is just packing some extra fat cells. If you see a puddle of runny poop, if there is no chicken acting lethargic, it's just a puddle of poop.

If, on the other hand, you notice the things I mentioned above and you see you have a hen acting sick, poor appetite, etc, then you have something you need to address.

Fatty deposits are not ideal, but some hens seem to be heavier than others in spite of being fed well with closely monitored treats. This isn't concerning in itself. But if you see a distended abdomen, the area in front of and between the legs, especially if the swelling pushes the legs apart causing the hen to waddle like a duck, then you may be seeing ascites, another name for liver disease. This isn't good. This hen will probably have only months left to live.

If a hen has a substantial pocket of fat below the vent and behind the legs, and especially if the skin appears red and the hen acts sick, that hen may have a chronic reproductive infection that might respond to an antibiotic if it's early enough to treat.

 

[Wyorp Rock]

She will sometimes act a bit lethargic but I haven't noticed her acting like that lately. I want to know what could be ailing her before it becomes something more serious.

She is a year and 4 months and yes, she is laying. It sometimes look like she waddles, but not really. Yeah, she doesn't really waddle.

Found a cracked egg in one of the nesting boxes with a weird red sack protruding from it, which I believe was a lash egg? I took out the egg and cracked the rest of it and found a beautiful orange yolk inside.

It looks a lot like this lash egg, but with more blood in the yolk. https://www.backyardchickens.com/threads/what-is-this-practice-wind-egg-lash-egg.914077/

If you actually cracked the egg open and it was a hard shell, then it was very likely not Lash Egg (Salpingitis), but an egg with a tail.

It sounds like your hen is probably doing o.k. - she's laying eggs, is not lethargic, looks like she waddles but yeah not really...

She may have a bit of extra fat and she's getting a little older, so I'd monitor her for now.
See that she's eating/drinking, check periodically to make sure her crop is emptying overnight and do routine checks for lice/mites. If you notice any of these issues, then address them quickly.

The link you posted previously looks more like an incased Intact Follicle https://www.backyardchickens.com/threads/what-is-this-gross-picture.1590786/