Red Hope your lil' guy is doing better =( imo it looks like a possible compaction. I would with-hold food and had I seen this earlier i woulda said to fast him/her. after a few similar instances w/ my 2 guys I now pre-soak their pellets and haven't had any issues since. it is possibly a pebble. But I would keep close watch for any signs of illness. and withhold food 24-48 hours and see if he slims out or if it gets bigger or if it stays the same. I'm not sure what possible things to offer as food to help ease him if anything is indeed stuck.. but packing more food in is likely to do more harm then good. If it was a pellet that was swallowed quickly and still verydry inside, it may take a few days to break down and pass, by fasting it allows for the space, and by feeding anything not thoroughly wet may just add to the problem. If it is a pebble fasting should encourage him to either pass it or toss it up. but he/she would have to throw up the other food first. Keeping my fingers crossed for him/her! if a few days of fasting and the bulge goes down i'de say it was compacted food. which id'e feed frozen or throughly soaked pellets for a few days and spareingly. and keep a close eye. If it stays the same I'de assume it is compacted.. and hopefully someone will have a good remedy/answer on how to deal with it. If it's worse.. I'de be worried about disease even if none is shown.
EDIT: I'm gonna bet compacted dry food. pre-soak pellets 'n feed lightly for a few days. -.-.. Bichir's 'r lil' piggies.. I get the "HI Mom! Food?!" just for looking at the tank...