What a shame when it looked like he had improved a bit. I guess the prolonged exposure to nitrite in the water has taken it's toll Don't know about the bloating I'm afraid, though i expect someone else will.
bloated tummy is a sign of dropsy, you need to look down on him from the top of the tank and see if like suey said his scales round his tummy are sticking out/looks like pine cone.
Could be swimbladder but doubtful. Sometimes it is so hard to find the right diagnoses.
If it is swimbladder, and suggesting by his white poo it could well be a possibility. Can he actually swim up to the top of the tank? I know he is poorly and probably wont move much but if he trys to swim up does he sink back down like he is being weighed down?
unfortunately Quattro has died today :'* I'm really upset as he was my first fish and very unique. I came home and he was on his side at the bottom. He's still lying there at the bottom im kind of hoping he's playing dead or something but I know it won't happen :( Aaah man I don't believe it :(
This is so unfair man ! Just can't get over it. I now have a empty 75ltr tank :(.
Thank you suey and stardust, are minnows coldwater? I'm thinking of going to tropical fish as I got a heater with my tank when I bought it. Going to give my tank a full clean, gravel, glass, the lot. Then put fresh water in and just let the filter clean the water for about a month until I decide what im going to get.