What could the cause be of very sharp lower-central abdominal pain and diarrhea?

Viral? Many different things can give you those symptoms. Diverticulitis, colitis, tumors adhesions/obstruction, ovarian cysts, less likely cancers can all give you sharp lower abdo pains. Is anyone else sick? If this is recurrent or has lasted more than a couple days i would see a physician asap. He/she will be able to examine, take a good history, obtain images. If severe, go to er.