So last night I woke up with nasty cramps and had to run to the bathroom (tmi) and had terrible…

So last night I woke up with nasty cramps and had to run to the bathroom (tmi) and had terrible diarrhea!!! I'm 20 weeks and this has never happened to me. I feel so weak and dizzy. I got up like 5 times through out the night. Has this ever happened to any of you? What should I do??? I'm trying to drink lots of water and all I had for breakfast was toast and a bannana.