Flowerhorn Cichlid Issue

Question
I have had an uncomfortable Flowerhorn Cichlid for some time now.
About a week ago and over a matter of 3 or 4 days she appeared to develop a large marble-sized lump on the left side of her body. No lump originally on the right side of her body, but now there is a slight protuberance. No scales protruding or scale loss, or other visible signs of sickness. She still has an appetite, though she has not been fed in approx. 7 days. Aside from bouts of turning dark and hanging near the bottom she appears to be her normal feisty self.
My initial suspicion was something bacterial in nature. We have been treating for 7 days w/ Maracyn2, and 5 days w/ Maracyn, and have not yet noticed any change.
Today the addition of Epsom salt to work as a laxative resulted in strange, greenish-yellow stringy poo....but not the apparent tell-tale white of a parasitic infection. Am I just being too color-specific? Can my fish in fact be infected w/ parasites and if so which is the best method of treatment? Local pet stores leave much to be desired in the treatment of parasitic infections!
Could it be possible she has swallowed a larger rock while digging in her bed?
Thank you so much for any advise you might offer!  

Answer
Hi Jessica
Some pet stores leave much more to be desired then just treatment for parasites lol...

Internal lumps are difficult to diagnose really.  It could be she swallowed a rock, that's common with cichlids.  I have a large red devil/midas that is always redocorating the rocks in his tank.  
Could be a viral infection, internal bacterial infection, a tumor, or parasites.  I would say your best bet to try to treat would be a parasite or antibacterial food since she still has an appetite(most pet stores carry these now).  That way it gets the meds inside her for better treatment.  

But, if it's viral or a tumor, chances are you won't be able to treat it.  Another thing too, make sure you're keeping the water quality excellent-ammonia and nitrites at 0 ppm, and nitrates ideally under 20 ppm.

The greenish poop you describe...not exactly sure on that one.  Could be because she hasn't eaten in a few days, just whatever's left over in her stomach.  Could possibly be since she hasn't eaten regular food, she may have chowed on some algae in the tank(?).   

Like I said, I'd try the medicated foods.  You've tried the anitbiotics, the foods will be less harsh then the parasite meds as well.  Other then that, I can't really think of much else to try, like I said, they're difficult.

Hope that helps, and good luck with her!  Let me know if you have more questions.

Christy