Why is my fish pooping so much?

Hello, I bought a balloon molly like 2 weeks ago. It had ick for a few days. I treated it by raising the temperature and adding salt. It's gone now. (only the molly) It poops sooo much. I don't even feed them that often especially now. I have a school project, psat and loads of homework. Anyways, I gravel vacced everything yesterday. And I see it full of poop. Why is my molly pooping so much? I never see my other fish poop before I got the molly, even if I overfeed them.