In searching for a diagnosis for my fish pooping white...I ran across this and it may be helpful to some in a pinch...
FRESHWATER FISH PARASITE TREATMENTS
Ichthyophthirius multifiliis & Trichodina & Ichthyobodo &Tetrahymena
Salt, formalin, malachite green, other commercial products, inc. temp.
Gill flukes, skin flukes
Copper, malachite green, formalin, others
External protozoa, flukes
Malachite green and formalin, others
Antiparasite medication, salt, copper, inc. temp
Fish lice, gill maggots
formalin, potassium permanganate, metriphonate, other commercial prod.
organophosphate, manual removal and then dab with antiseptic
Larval stage of digenetic fluke parasites
organophosphate, other commercial products
Hexamita & Spironucleus
Metronidazole, other commercial products
If flukes: praziquantel, others difficult to treat
Use of appropriate anthelmintic drug, eliminate IM host, remove dead fish, piperazine
Difficult to treat, praziquantel
for parasites try giving your fish a salt water bath. one time i thought my fish had ick are so thats what it looked like i raised my temp to 85-f and got a bucket put a heater in got it to 85 caught my fish put them in one at a time and i could watch the parasites come off . the fish didnt like it but it cured them right up 3-4 mins per fish put them back in to the tank and it was gone