Help with diagnosis treatment of vent problem

I have a 1 1/2 year old Barred Rock that I got second hand. She came to me as a small chicken, she seemed too small to be 1 year old as they said. Anyway she has developed some vent issues. It could be a prolapse, it could be Ascite (water belly), it could be an egg that didn't fall down, or I don't know... I just gave her a soak in mineral salt water and she is still lively enough to complain. Her vent protrudes and is featherless and red. And after bathing I notice a red nodule protruding up from her tail bone, the tip of which is white-ish. It is tubular and about 1/4 inch high. She tries to peck at it. Her crop looks fuller than it should for the amount she is eating. She drank excessively one day after coming inside to an indoor cage. She is eating, but not a lot. Her poop is someone normal but runny and at times yellow/white. She still stands and hums a little (she misses her 4 sisters). She is not at death's door, but heading there if I can't figure this out. It may mean a 40 mile trip to the only bird doctor in our valley here in western Colorado.
I gave her a does of Ivomec about a week ago just to make sure mites weren't a problem. I have also tried small amounts of hemorroid cream that may be reducing the redness. Her comb and wattles are red, maybe a deeper red than they should be. So I tried a dose of baby aspirin (liquid) that may also be helping with redness. She is inside out of the 20 degree or less temps. During the day she's in a sunny room and at night she is in total darkness - I don't want her laying.
Since adopting her, her eggs have been larger than normal with thinnish shells - too large for her size. My chickens have access to oyster shell but I can't be sure who is eating what. I don't think she was in exceptional health when I got her and I may not have brought her up to strength since...
Any help is welcome.

 

I'm sorry I didn't get good photos. She was extremely red and featherless on her bottom. Since posting I found some threads that suggested vent gleet caused by a fungal or candida type problem. Nystatin was suggested. Several places sell it for birds under Medistatin online. The closest for me was a place in California who sent it right out. After a treatment of that her rear is back to a normal color. The problem may have put her into a general molt. She lost feathers all over and is now just getting them to grow back including her nicely colored butt.
Due to the high-protein need for growing feathers she began walking like a drunk. Threads and posts suggested this isn't life threatening. I am upping her protein consumption and providing probiotics. She is walking less drunk.
Next problem up for her is that she now has diarrhea that she didn't have before (that I noticed when she was outside). Very liquid with lots of white. As far as I can tell from the postings and threads, this might be an indication of coccidiosis. So I have some Corid solution on the way for that.
I'm wondering if the coccidiosis was the initial cause of the vent gleet or fungal/candida problem to start with. If anyone can weigh in on that I'd be grateful.
She was a second hand chicken and I'm not so sure she came 100% healthy.
She is a real trouper, tho, an excellent patient who is allowing me to try everything till I get it right. She had epsom baths to start with for the butt problem as well as some human woman's Monistat applied topically; and before the Medistatin arrived I gave her oral solution doses of tetracycline as that was the only thing I could find locally. She may have had a cut on her foot. I don't hold my chickens upside down, but I held her on top of a mirror and it felt and appeared like a healing cut.
She may have had multiple problems that had weakened her. I hope I am not a Munchausen syndrome by proxy chicken owner, but if I didn't do something she wouldn't have made it through our cold Jan. In general she is doing better than when she came inside to her ICU cage.
Thank you to all the postings and suggestions.

 

Update. In my opinion, I think the Medistat really helped Poppy with her red behind. She also had lost feathers on the top of her head right behind and around her comb - those small head feathers, as well as feather loss at her wings and undercarriage. She had some major problem raging through her system. The epsom baths, the topical Monistat cream, the probiotic yogurt all may have helped - but I think I saw the most improvement after the Medistat (Nystatin). I'm not sure what caused the watery diarrhea (she still has) - but a treatment of Corid hasn't gotten rid of it. Hopefully it will right itself once her heavy molt and regrowth of feathers is complete. I read one post somewhere that said they can have watery stool after a molt - don't know whether that is a fact. Her drunken-walk is all but gone.
She seems to be eating more of her regular chicken food and I am relying less on mealworms and treats to get her to eat. I don't feel anything peculiar in her crop.
She definitely has never been a shrinking violet personality-wise, that helped her get thru.
I think her next real problem will be establishing herself back in the pecking order. She was out for some fresh air time this sunny morning with the other four hens and I saw my big-ole' tank of a girl, Marigold, giving her the evil eye.
I hope to post a photo of a nice healthy bird soon.