Flowerhorn Fish pooping ligh blood red

Question
I have a flowerhorn fish.  It was in a 10 gallon tank.  It stopped eating about 2 wks ago.  It seemed stressed so we put it in a 30 gallon tank.  It seems to be doing better, but still not eating.  It's been pooping white poop and then yesterday, this poop, 1/2 inch in size, light reddish, is starting to come out.  We called the fish store as all of this has been going on, they said that he might have a parasite.   So, we started treating the tank with maracyn.  This red thing still, red, big, poop, seems to go in and then comes out again.  I don't know what it is.  Please help!  We don't want the fish to die.  Thank you.

Answer
Change the diet to something with less protein and more nutrients. Have it in small pieces so it won't get bound up. Otherwise, just keep using the treatment and you can even call your local aquarium to get more advice.

Keep doing regular water changes as well, hope the fish survives!