What kind of substrate do you have? I had a fish with the same symptom. It was difficult to watch the fish try and do the things it normally does like feed or schoal with the others. I decided to humanely put it to rest. Moments after it passed, it released a lot of sand.
I don't know if swallowing the sand caused the bent back because I didn't allow enough time to find out (course I had no idea at the time). It's just a thought but all of this is mute if you don't have a sand substrate
I don't know if swallowing the sand caused the bent back because I didn't allow enough time to find out (course I had no idea at the time). It's just a thought but all of this is mute if you don't have a sand substrate