I am a 64 year old woman. About three weeks ago I noticed on several bm that I had bright red on the outside of my stools. I had increased my fiber by quite a bit so I thought with the increased size and frequency that my hemmorids were bleeding from the straining. I also was getting cramps when I had a bm. Last week I noticed mucous twice. I made an app't to have a colonoscopy but am worried. Since then the cramps has gotten better, do not have them at night just before, during and after a bm. My stools keep changing from brown, to oily yellow to green with black spots. cancer or could it be ibs. No more bleeding, just cramps and loose stools of various color.