Did you feed live, frozen or freeze dried worms? Sometimes the outer casing is not fully digested. I wouldn't worry too much if it's just the 1 time. But if it continues or you're not feeding worms, meds might be a good idea.
I've rarely treated fish & corys can be sensitive to some drugs. Praziquantil/Metronidizole combo (some have both, some have only 1) OR flubendazole might be in order. I don't know if those are easily available in Canada...
When I have drugged fish (mostly loaches with Levamisol or flubendazole only), I tend to do a half dose & wait 8-12 hours to add the other half. I watch for signs of distress: fast breathing, paleness, red gills, lethargy or anything that looks "off". Be ready to do a large water change. They may or may not eat normally but a few days fast won't hurt them either. Watch carefully if you go that route & redose as indicated on the label.
You might look at planetcatfish, that my "go to" for solid info on cats.
I absolutely hate!! tubifex worms in any form...but especially freeze dried! That's just my experience from many years ago. If that's what you've been feeding., STOP now! I'm not a huge fan of freeze dried blood or black worms for most fish, but I did use them as part of a huge variety I fed juvenile discus. Too floaty for my bottom feeders even with long soaking.