abdominal pinching

Hello! I am a 39 year old women who is in good health. I started passing blood in my stool after running. As a result I had a colonoscopy in July 2008. It showed inflammation of the rectum. I have taken Canasa but not currently.

About 4 weeks ago is started having these random pinching sensations in my abdomen which were near the navel. I mentioned this to my Gastro. Dr. two weeks into the pain and she dismissed it as as stomach bug. I still have them but had a severe case of diarrea (diarrhea) this weekend. The stool was very light and now I have been having green colored bowl movements.

Had and abdominal ultrasound recently and my ovaries and uterus are o.k.

Any clue as what the heck is going on????