I had plecos in my 25gal tank, and id drop algae tablets in there and all the fish would eat it. I think its fine, mine all seemed alright, but i was just going on what i thought. you could try using zuccini instead, take a slice of zuccini and put it in hot water for 5 mins and drop it in the tank (it should be a little bit soft)
then stick part of it under a decoration or something, and try and hold it down.
Not sure about the bloated stomach though, but maybe he'll leave the zuccini alone?