I Have Had Diarrhea For 24 Hours Probably On Average

I have had diarrhea for 24 hours probably on average 2X per hour. After the first few few I have noticed there is very little but it looks like mucous. On top of that it looks to be bright red blood mucous and when I wipe it is all bright red. I also have abdominal pain that gets really painful before having to go. The systems came on out of nowhere and have have been nauseous since they started (haven't thrown up though). I recently got back from 2 weeks in Italy. Just wondering how long this might last? What it could be? If I need to see a doctor? Thanks!