Definition. The erythrocyte sedimentation rate (ESR), or sedimentation rate (sed rate), is a measure of the settling of red blood cells in a tube of blood during one hour. The rate is an indication of inflammation and increases in many diseases.
Having blood in the stool can be the result of a wide variety of conditions, such as hemorrhoids, diverticula, inflammatory bowel disease, rectal prolapse, colorectal cancer, rectal abscesses, intestinal infections, peptic ulcer, intestinal polyps, constipation or anal fissures.
Bloody stool (stool that is very red or has streaks of bright red blood in it) is called hematochezia and usually originates from the colon or rectum. Melena on the other hand, is generally caused by bleeding within the stomach or small intestine. Various Causes of Black Stool. But what causes this upper digestive bleeding in the first place?