Yesterday, my 2 smaller goldfish started chasing my bigger goldfish around the tank, pecking at his anal hole. I think he may be constipated becuase a bit of poo is came out but has come out no further, and the other fish have mistaken it for food, even though I feed them reguarly os they can't be hungry. What should I do? I am worried that this harrassing is making him very stressed. What if the other fish even DAMAGE his butt by all the pecking? I've heard that peas help a constipated fish, but I have no idea what else to do. What if the 'poo' is something more serious? A tumor? Please help!!!!!