Hi so my mum has kept three puffer fish for the last year and have been doing fine, but one of them has developed a really swollen belly with lumps bulging out, he is still swimming normal and eating and the other two are fine, but the lumps are getting bigger and now his anus its starting to open up really wide!!! could this be constipation???? Any help would be great I don't think he is going to make it but would really like to know if this has happened with anyone else?