Blood in the Stool: Explanation of Various Terms for Gastrointestinal Bleeding or Hemorrhage
Gastrointestinal bleeding:
Bleeding in the GI tract is very common. It should not be ignored because of its potential serious causes and life threatening results. Understanding basic terms and definitions used in GI bleeding will make it easier for you to recognize GI bleeding in yourself or a family member, communicate more clearly to your doctor about your symptoms, and search more effectively and accurately for information. You will also be a more educated and effective advocate for yourself so that the cause can be diagnosed and treated accurately and in a timely manner.
Blood in the stool:
Blood in the stool or gastrointestinal tract may take various forms or appearances depending on where it is coming from and how brisk the bleeding. There are common medical terms and definitions for blood in the gastrointestinal tract or stool that may not be familiar to the lay public but can be helpful to know if you or a family member experience gastrointestinal bleeding.
Hematemesis is vomiting blood:
Red hematemesis is vomiting red blood. Coffee ground's hematemesis is vomiting blood altered by stomach juices.
Blood in the stomach is quite nauseating usually resulting in vomiting. Vomiting blood is called hematemesis. It can be bright red if occurring briefly after the blood enters the stomach or when the bleeding is brisk. Stomach acid and digestive juices alter any blood that remains in the stomach. If the altered blood is vomited, it usually appears like old coffee grounds, hence the term "coffee grounds like" hematemesis. Blood may originate from the stomach, be swallowed, or regurgitated from the duodenum, the first part of the small intestine just after the stomach.
Melena and blood as a very potent laxative:
If blood in the stomach is not vomited completely the altered blood passes into the intestine where it usually triggers diarrhea. However, the diarrhea is usually black, tarry and foul smelling. This is termed melena or melenic stool. Though many doctors mistakenly refer to such stool as melanotic that is an incorrect term. Melanotic refers to containing melanin, the dark skin pigment present in moles and the malignant skin cancer, melanoma. Melena or melenic stools indicate an upper gastrointestinal tract bleed or source of blood because it has been altered by digestive juices only present in the stomach and upper small intestine. Such bleeding usually originates from a site reachable by an upper scope though occasionally the site is beyond the reach of such a gastroscope.
Lower gastrointestinal hemorrhage and rectal bleeding:
Red blood passed rectally usually indicates the source of bleeding is in the lower colon or rectum, or lower GI bleed, except in massive hemorrhage from the upper tract. Bright red blood on toilet paper or dripping in the toilet bowl is usually from the anus or rectum, most commonly from hemorrhoids or an anal fissure, though can occur with rectal cancer.
Bloody diarrhea and colitis:
Bloody diarrhea, often with mucus, is typical of colitis. Colitis is inflammation of the colon or large intestine from any of a number of causes that may include infection, poor blood flow to the intestine (ischemia) and the chronic inflammatory bowel diseases ulcerative colitis and Crohn's disease.
Occult blood in the stool:
It takes about 50-100 ml blood to turn the stool black or melenic. Less than 2 cups of bleeding is therefore not usually visibly detectable and is termed occult blood in the stool. Various chemical tests for occult blood in the stool exist that can be done on evacuated stool or stool obtained by a gloved finger exam by a doctor. Occult blood in the stool is concerning for cancer and necessitates an evaluation for the cause. Ulcers, acid reflux, Celiac disease, polyps, colitis and Crohn's disease, hemorrhoids and aspirin type medication injury to the gastrointestinal tract are all common non-cancer causes of occult blood in the stool.