What is the definition or description of: gastrointestinal bleeding?

As pointed by GI Ble: The words provide the definition: Gastro or Gastric means stomach; Intestine means bowel. So it is the term sued for bleeding from the stomach or from the intestines. Since they are linked together, blood can go out via the mouth( if coming from the stomach) and though a bowel movement if the source is anywhere in the digestive tract(stomach as well as the intestines).

Blood in GI Tract: A long tube runs from the mouth to the anus. It includes, in order, the mouth, throat, esophagus, stomach, small intestine (duodenum, jejunum, ileus), caecum, the ascending, transverse, descending, and sigmoid colon (or large intestine) and the rectum. The space inside that tube , the lumen, is considered to be outside of the body. When we bleed into that space its called GI bleeding