I have had blood when I wipe and on the outer part of my stools on and off since February. I am a 28 year old female and in January of 2006 I had a colonoscopy which was normal. This February 2007 I had a rectal exam done by my family doctor which he said was clear. However I was still experiencing the bleeding, pain under left rib, and nausea so I had a CT scan done of abdomen and plevis with iodine and everything came back fine. Is that enough testing to rule out colon cancer even though I am still bleeding and every now and then am constipated. The only change in my lifestyle is that I had a baby 7 months ago in which I did have internal and external hemmorhoids after delivery.