What Is This?

My Torpedo bard got this after 5 months of being in the same tank- not sure what it is but will take any info people have, thanks.

250L tank
Good circulation + airflow
40% waterchange per week
Only 6 torpedo barbs + 2 Plecos in the tank

Hard to tell from the picture what you want us to see. To me it looks like something is coming out of the anal region? If yes, look up callamanus worms and pray that that isn't what it is Can you post another pic?

could be herniated, which is harder to treat but not contagious.