Pleco with swollen belly

[PlecoLover2721]

One of our L066 is really fat and has been for over 2 weeks, we've been feeding him pees, but he is still fat, and if anything is only getting bigger. I think he may just be constipated because this hasnt spread to anyone else in his tank. Im just wondering if theres anything else i can do, ive read about Epsom salt but heard bad things about it, especially Epsom salt baths.
nitrate is in between 0-20
nitrite 0
PH 7.25
KH 180
GH 60
Temp is 83F
change 25-30% water one or more a week
tank is 55gal with 2 L066, 1 L333, 2 L260, and 3 cory julii's.
we've had the tank set up for almost a year, most of these guys used to be in a different tank.
We feed them shrimp pellets, algae wafers daily, and frozen shrimp once a week or so.
Thanks for any advise.

[PlecoLover2721]

Heres a update on this, now the entire tank is starting to have swollen bellies, ive started treating with api general cure for the last 4 days at the recommended dose. Ive heard that some internal bacteria can cause swelling, but haven't found a medication that say anything about swollen abdomen, so not sure what to try. Also I did see one of my guys pooping, it looked normal not clear or anything so I don't think this is bloat.

[Unungy]

Hi.

I will treat it with Metro (Metronidazole) for 5 days.

day 1
50% water change
Full dose
day 2
nothing
day 3
50% water change
Full dose
day 4
nothing
day 5
50% water change
Full dose
Six day
50% water change

You will see results on the second day but don't stop the treatment. Unfortunately I use pure powder and the concentration is very different so I will recommend you to read the instructions provided by the supplier for the correct dose. Metronidazole can be poisonous and it will kill all your plecos if the incorrect doze was applied.

[PlecoLover2721]

Thanks for reply, I have had it in the tank for 5 days now. Mine says do one dose, wait 48 hours another dose, 25% water change. that's one treatment with the api brand metro I have. I haven't seen any changes in there swollen stomachs so im not sure if I should do another two doses. Do you think it could be something else? Ive heard of some internal bacterial infections that swell up the stomach. or what about bloat? I haven't had any experience with that.