I have been having diarrhea the last few days, can that cause my blood pressure to go up. thanks?

Not typically: A few days of diarrhea would more commonly cause lower blood pressure if you are not drinking enough fluids. It is possible that one's blood pressure could go up with a few days of diarrhea if you are not taking your bp meds or not absorbing it. If there is associated nausea/vomiting, or the diarrhea is so severe that your blood pressure med is not being absorbed, your bp could increase.