"Guys can house mold be causing nausea, diarrhea symptoms?"

House mold can make you very sick. My guess is that nausea from it could be very likely, however diarrhea from it might not be so likely.

If your home has mold, you need to deal with it. If it is not so bad, you can get rid of it with Tilex or bleach. If it is very bad, you might need to hire someone to fix the problem.