More Tetra Trouble :(

[BadBadger]

Just noticed one of my rummys has a very red belly. Its not quite his belly.... Its hard to explain. Its like his intenstines or something. He doesnt seem to be behaving any differently. Im trying to get a picture but its quite hard haha

can anyone help

 

[loraxchick]

Is the fish flicking off the substrate or objects in the tank? any bullying? What kind of food are you feeding and how often?
cheers