Ben 11, I just was released from the hospital with a severe case of C-Diff. It is diagnosed through your stool samples. Usually one will have a fever, have many bloody stools, D, and waves of intestinal pain. As was mentioned above, it is very distinctive but can also at first be confused with a flare. Flagyl didn't work for me the first round, and I ended up in the hospital for nearly five full days on IV antibiotic of flagyl and liquid vancomycin. Not on my list of do-overs!