Help ... 32weeks and can't stop

Is it normal - as I've been stressing my self out looking in the Internet ... 32 weeks exactly and (sorry for over share) I have horrendous diarreah! I had an episode at 30 weeks for a few hours at 3am where I had it ... And was sick at the same time ... Now I'm 32w today and have been off and on the toilet for the las 36hours ish! I have work tomorrow and it's awful! It just comes on suddenly like a wave and I have to go ! Is this notmal?