Thus far there is zero evidence supporting the use of
any form of anti-parasite medication on this fish, as there are no visible (or otherwise) signs of internal, or external, parasites. Waste of $$$, and potentially further stressing an already stressed fish!
The use of epsom salts (not 3%)
in the tank water is to assist in the reduction of fluids, which "sometimes" can help the prolapse be reabsorbed by the fish.
From the link previously posted:
With an external prolapse it's the wall of the fishes ass hanging out, not his intestine. That's why it's called a rectal prolapse.
Water quality is not the cause.
In humans these are some of the more common causes:
•Malnutrition.
•Deformities or physical development problems.
•Straining during bowel movements.
•Infections.
Also in humans, often times surgery is the only corrective action that can be taken. Which is also why Tom and I both stated sometimes they retract back into the body, and sometimes they don't. The longer this goes on, the less chance of a full recovery.
If there's anything med wise that should be added, I would lean towards a broad-spectrum bactericidal, such as what Wailua Boy mentioned earlier on. Personally I would take a wait & see approach first, then follow up with an antibiotic only if the epsom salt treatment failed. If you need to go that route, this will help.
http://edis.ifas.ufl.edu/fa084