I have been on antibiotics almost all winter long, and thought I felt a lot better. I have been going to the gym and working out and trying to lose a few pounds, when suddenly one morning I woke up with terrible nausea and horrible abdominal cramping in my lower abdomen. I can honestly tell you it was as bad if not worse than labor pain!!! I did not have a fever, but on my ct scan, the appearance of my colon was very uneven and knotted. I have been taking flagyl for about eight days now and sometimes I actually think I am improving. I am still somewhat bloated and still sometimes nauseous, but I know that my doctor is on top of the situation. I did not know this was contagious though, and will strive not to spread it to my family.