Blood in the stools indicate that there is
some bleeding in the intestinal tract.
If blood origins from the esophagus,
stomach or duodenum the blood will be
black (melena) because of the stomach acid
impact. Melena can be due to swallowing
blood, bleeding esophageal varices,
bleeding from stomach or esophageal ulcer
and bleeding from stomach or esophageal
tumor.
If the blood is fresh (rectorrhagia) it
means that the blood origins from the
small intestines, large intestines or anal
opening. Blood can origin from some
intestinal tumor, bowel inflammation
(colitis) or hemorrhoids.
Sometimes blood in the stools can be
invisible and can be detected only with
occult blood test.