I am now experiencing black stools, and I have had sharp severe pain that only lasts about 10 seconds in the lower right abdomen and my stomach is making extremely loud noises, it sounds like a toilet flushing or a very loud bathtub drain. I have had black stools for past week -90% are black, have also experiences the same about 2 months ago and sporatically since then except for the past week. Last colonoscopy I had was 4 years ago. I had negative blood occult in March.