Broody, vent gleet or worse?

My wife called me at work and sent this photo of our oldest chicken:

She was a neiborhood stray that we caught and brought home years ago, and she usually avoids us at all costs, but she isn't doing that right now.
My wife has sprayed off her butt and was looking for a container giver her an Epsom salt bath in.

This is what the hen butt looks like after a 10 min Epsom soak.

I'm VERY new to chickens so please take my opinion with a grain of salt.

It looks like a bit of swelling, so I would start treatment as if it was vent glee and go from there. Keep the area clean, keeping warm, isolation if possible to keep an eye.

I have heard a 14 day treatment of anti-fungal creams (Athletes foot) might be of help but I haven't done a deep dive on the pro's and cons.

Wishing for the best.

OK, first off, if she was broody she'd be finding a spot and building a nest, so I'd strike that as an option.

Second, do you have an approximate age? How long has she lived with you?

Third, do you have any idea if she's been laying regularly? If so, how has the egg-shell quality been?

I found this interesting article: https://www.bhwt.org.uk/hen-health/health-problems/vent-gleet/

and this item 3 in particular:

Add apple cider vinegar to drinking water and provide a probiotic daily.

Apparently, chickens like yoghurt so that would do the job.

She's about 5 years old and I don't think she's been laying .
I will offer her yogurt and maybe some lacto fermented grain.

I recently threw them some old corn that seemed to have weevils.
Now I'm wondering if that could have caused this, but that does not fit what I know about chickens and bugs.

Five years is old for a layer, depending on how much she laid. If she'd stopped laying and was just starting again, it is quite possible that she tried to lay an oversized egg and is egg-bound (Epsom salt baths and dietary support is all you could do for that if it is the case.) Alternatively, she tried to lay a weak-shelled egg and it cracked inside her and she has an infection.

I would do what you're suggesting and make sure she's got a safe place to rest if the other chickens are hassling her, but I think you're in a warm enough climate that "keep her warm" isn't needed at this time of year?

Howdy and I hope you've seen an improvement in your hen's health.

It wasn't the corn, weevils or not.

The red spot is what's throwing me. Is it hot to the touch? Is it swollen? That's not a normal thing for a hen, so I really want more information on that.
I'm thinking it might be an infection of some sort.

If you can palpate her abdomen gently, you might be able to supply a little more information about her possibilities. I'm thinking that, if you're having the kinds of temperatures that are everywhere else (record breaking heat),  she hasn't been laying. She may have a simple infection caused from a combination of being too hot, laying around in cool spots, and ... things happen.
She may have egg binding. She may have peritonitis. Heck, she *may* have any number of horrible things, but the odds are pretty good she doesn't.

What you're doing, Epsom salts soak, keeping her clean and dry, providing her with lacto-fermented foods, offering her yogurt, giving her clean water, good quality foods, and keeping her as comfortable as possible will go a very long way to helping her get better no matter what's going on.
Just like with people, start with the basics and fine tune as you start eliminating potential causes/reactions.

If, today, she still has that red spot, she needs an exam. You can do it. Just hold her and gently give her a very thorough massage - basically. You're looking for any hard spots that aren't easily identified as bones. Or anything that seems exceptionally hot or tender to the touch.
There are vitamins and minerals formulated for chickens that you can give her that will help her fight off an infection. Rooster Booster is the easiest brand name to find, but you can make up similar things at home.
Basically, electrolytes - Apple Cider Vinegar (up to 3 tbsp per gal of water), a little honey (a dollop, about a tbsp per gal), and a little salt (about a tsp per gal) - you want the water to have some good stuff in it, but you don't want to stress her  kidneys - is a good basic start. You can always add more or less of whatever, this is just a starting point for a very mild chicken energy drink.

If you've found a puncture wound, clean it out well and use your personal favorite wound treatment. What works for you, with a few caveats, will work for her. I save a lot of my older Over The Counter wound treatment stuff for use on my birds.

I hope she's doing better today. My best thoughts are with y'all and her.

Thanks for all the great advice!
Some people don't get the relationship I have with the hens as domestic animals that are not food or pets but  sometimes more like partners, but permies seem to understand.

Soon after her first bath I had to leave town to deal with a family emergency, a car wrecked on the road , no injuries,  but more than an hour away from home.
My wonderful FIL fed and watered the hens while I was gone, and probably gave the dog a steak(he's a sucker for animals and children).

Our ailing hen was both well and awake enough to avoid me when I returned at dusk today.
I will be nursing her sore bottom again tomorrow morning,  when I can match her energy, and get the drop on her as she leaves the coop!
I know she's old, but I think she could live at least 3 more good years if we get her healed up.

One belief I have about animals is that, for the most part, if you can't catch them to give them a medical treatment, they're in pretty reasonable health - with a few obvious exceptions.

I have been able to teach dogs and a couple of cats that dewormer medication (heart worm pills and the occasional other things) might be a treat. They might not be excited about the prospect, but I don't have to wrestle them, either.
I haven't had to worry about that with the chickens, yet. They do get some infrequent medical checks, but generally regard me as The Source of Good Things or The Food Bringer. I don't chase them or handle them if there isn't a reason or they initiate contact, so we're "hang out buddies" and they'll come and talk to me. I like the chill, casual vibe and they seem to enjoy hanging in my general vicinity, so I'm pretty sure they get something out of it.

So, yeah. Livestock, but still companions of a sort. They might end up in a stew, but I work hard to make sure they have the "One Bad Day", if at all possible.

You aren't alone in thinking fondly of your birds while still keeping a little distance. Not quite pets, not quite "just a chicken".

Yesterday, before I went back to people care, I soaked their feed in sauerkraut juice.
I snagged the hen in question (her name is Rebel) when I went to open the coop.
We had an inspection, followed by a butt soak, followed by an inspection.
I do not know how my wife managed to take photos during her interactions, I needed both hands to quell this chicken!

Anyway,  she is still looking red, the vent looks good, and I found no swollen or extra firm spots with a manual exam.
My wife filled me in on details of her FIRST bath: Rebel was sitting on top of the gate that leads into their run, and would not shoo.
Normally she avoids being near  us as much as possible , so that was weird.
Since she was using the hose anyway, the wife squirted her - and still Rebel stayed put!
That is when she snagged the hen and began examining her.
This means the first photo showed her already soaked,so no feathers are actually missing!

Maybe we overreacted, but the behavior was really bizarre for that particular hen.
I might bath her again, but before I do, I need to check the other girls.
The redness I see on Rebel may be a reaction to mites or something microbiologic
I'd just cleaned the coop, but hadn't  added new bedding, so that has been done.
I will be misting the coop and bedding with lacto bacillus solution and dusting the coop and hens with DE.
I've not checked the soaked feed, but hopefully they liked it.

Thanks everyone for the support!