Elephantlover, c. diff. is a bacteria, the mind-bending name is
clostridium dificil. When we're sick or having a flare, or when we're on antibiotics it will tend to grow and infect our colons. It is the big new concern in hospitals, because a lot of people pick it up there, most likely because they're sick and it's around in other patients. Because the normal, "good" bacteria tend to get wiped out by UC, it leaves a wide-
open door for it to infect us.
The reason I thought of it is that it tends to cause watery diarrhea and very severe cramping. UC flares can also do this, and the only way to be sure is to have a stool culture done. Thus, my suggestion about the stool culture.
Hope you're feeling better soon!