The bowel fluctuations turn bloody and painful, causing too much discomfort. Mind the bowel movements and compare with your regular condition! Have you noticed a deep red or even black colored blood when attending restroom? It is a good sign to contact specialists. Think about how much iron-rich food you supply as it might be another good explanation. If you do not consume that much iron, the reason why your bowel movements are followed by dark colored blood streams might be as bad as the stomach cancer.