From what I've read, it could be constipation, or a tumour. I really hope it is just constipation. I recently started using a different betta food because the store was out of the kind I usually get. I hope that's all the problem is. But he is about 2 years old, which is the usual lifespan for bettas though some have lived up to 5 years.
Originally posted on the late great Vegan Porn.