Fish intestines???

[plank]

My Discus has what looks like a large maggot hanging from its underneath. I cant work out whether its the intestines or an actual worm. Other pictures of worms seem too small and thin for this to be one. The fish has not been eating very much for months and has grown very little since we purchased it a year ago.
Please help, its disgusting!

[ILLUSN]

sounds like a tapeworm to me, get it onto the prazi.