Identified by a protruding anus, a rectal prolapse can be caused by constipation, straining or even unknown parasitic infection. These things will usually correct themselves and adding vitamins to the food and dosing kanaplex can help with keep it from getting infected while it’s out. Premium water quality should be a priority during and after this time as well. On larger fish who don’t appear to be getting better, it’s possible to correct the issue yourself and use a purse-string suture to keep the anus inside the body until it’s healed.
I was surfing the web prior and came about an infection called "Camallanus Worms" which looks similar to what the fish has. I took a photo form a different angle and some videos to give you more of a 360 scope of how it looks. Let me know if it's anything different than what you have mentioned. If not then I'll proceed with the guideline.
Also just an fyi I live in Canada so some treatments like Kanaplex are not readily available. I have something called Melafix, some Metroplex laying around from a purchase I made last year, and aquarium salt. Would those do the trick instead? Appreciate the help