I had the same thing earlier in the week, & when it was all over, the endless D, cramps, nausea, etc. I was left with bright red blood in the toilet bowl, over & over for about
4-6 hours. It lessened, the blood, but I've been passing pink mucous ever since. Finally this AM, I had my first actual bm since Monday! No blood!!!! Well, a little... I haven't seen that much blood since I was in the midst of a really bad falre, a few years back- it totally freaked me out. But, I seem to be on the mend. GI bugs really do a number on those of us with UC.