Sick Guppy?

Question
I have a male blue Guppy who was bloated and pooping long hairlike white poop. I put him in hospital tank for few days and didn't feed him.  Now he poops brown poop a few times a day and isn't bloated.  I put him back in his tank and then he started to look sick.  I moved him back to hopital tank. Now I see a small hole on his right side. It started as a lump.  All the other fish are ok. He is active by himself.

Answer
Theresa,

It sounds like he had a boil on his body. Keep him in the hospital tank and treat him with salt baths. Check the water readings in the main tank for ammonia and nitrites. As long as he is still active and eating it's a good sign. Is he bloated now? If so, fast him for 2 days. On the third day feed him a cooked shelled pea and then fast him again for 2 days. Do not over feed the fish. Only feed what they can eat in 2 minutes and remove any uneaten food right away. Let me know how he is doing after the salt water bath. Do you see any parasites on him or in the tank?